Glaucoma

The normal eye is filled with a fluid called the aqueous humor, contained at a pressure of around 10-21 mm of Hg. The most important thing to understand about glaucoma is that it results from an increase in intraocular pressure (IOP). Most of the time, even when the patient has a high IOP the patient has no symptoms. The real damage is done, however, to the optic nerve at the back of the eye, which sends vision messages to the brain, and this can cause severe vision loss if left untreated. Glaucoma is incurable and damage incurred prior to treatment is irreversible, so it is important to be aware. Again, the most difficult thing about glaucoma is that it often has no symptoms until enough damage has been done to create noticeable vision loss. Only a few patients will have symptoms which can be chronic headaches or nausea, as well as blurry vision or pain after eyestrain. The loss of sight begins with peripheral vision and then works its way to the center of the eye, so one of the first diagnostic procedures for glaucoma will be a vision test of peripheral vision.

Glaucoma is actually an umbrella term that includes any of the several conditions that involve a hardening of the eye. It is most simply broken down into primary and secondary glaucoma. Primary glaucoma occurs seemingly spontaneously, meaning it is in no connection with another eye disease. Secondary glaucoma does have some such connection. Primary glaucoma can be broken down into Non-congestive / Chronic Glaucoma or Acute / Congestive glaucoma. The latter is more quick and dramatic than the prior, which happens slowly over a long period of time.

There is no one cause of primary glaucoma, which makes it difficult to predict. It is possible for glaucoma to be passed on congenitally from parents to children, and juvenile glaucoma is not easy to diagnose because many children do not know how to talk about or describe any problems they may be having. Some glaucoma is caused by improper drainage of the eye while other cases are caused by an increased production of the aqueous humor.

After understanding all of these pieces of the puzzle what can you do with a glaucoma diagnosis? The most common treatment is eye drops, which can help to regulate the aqueous humor production and drainage, and can be very effective at stalling or possibly stopping the eye damage if they are used consistently and correctly. Other surgeries and laser treatments are offered for more extreme cases. It is possible to become blind as a result of glaucoma, though efforts are always being made to learn more about how to predict, prevent, and treat this condition.

Contact us by phone or email… or visit our office today!

New Low Vision center or Vision Rehabilitation center has opened!

New Low Vision center or Vision Rehabilitation center for the treatment of glaucoma related vision loss has opened on Belmont St. in Cambridge! We are excited to offer tools and aids to make reading and distance vision easier and more accessible to our patients with reduced vision. Our Optometrists take the time and make the effort to demonstrate the use of different vision aids to our patients. We have access to many different companies offering the latest and greatest low vision aids on the market. Click here to find low vision specialists that can help treat glaucoma related vision loss.

 

Sources:

Eugene M. Blake

The American Journal of Nursing, Vol. 52, No. 4 (Apr., 1952), pp. 451-452
Published by: Lippincott Williams & Wilkins

Glaucoma

Trope, Graham E. Glaucoma: A Patient’s Guide to the Disease

Glaucoma: Types, Symptoms, Diagnosis and Treatment

A Patient’s Guide to Glaucoma
By Young H Kwon, MD, PhD; John H Fingert, MD, PhD; and Emily C Greenlee, MD
Edited by Young H Kwon, MD, PhD

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Conjunctivitis

The conjunctiva is the clear mucous membrane that envelopes the rest of the eye. Conjunctivitis, commonly known as “pink eye,” is caused by the inflammation or irritation of the conjunctiva, and has a variety of forms with the same symptoms of red, itchy, and burning eyes and perhaps some secretion of discharge. Although it is normally clear, the conjunctiva houses all of the eye’s blood vessels, and so during any irritation these blood vessels swell, giving the eye its pinkish glow.conjunctivitis-pink-eye It is important, to know what has caused your case of conjunctivitis to ensure that you have done all that you can to cure it. For a consultation, contact us today.

Unfortunately the most common type of conjunctivitis has no cure other than time. When pink eye is born of a virus it can clear in a matter of days, and it is contagious as long as symptoms persist. It can be passed very easily through any contact with the eye or through shared items like towels and toys.

It is important to maintain vigilant hand washing and to wash or disinfect anything that could serve as a conductor for the disease. It is this difficulty that makes pink eye rampant in day cares, schools, and college campuses.

Viral Conjunctivitis

Although viral conjunctivitis has no medicinal treatment, bacterial conjunctivitis can be cured with antibiotics, and it is for this reason that you should always talk to a healthcare professional when you think you have pink eye. After 24 hours from the first treatment you may return to your daily activities with no fear of spreading the infection, even if the eye has not been relieved of symptoms yet.

pink-eye-symptomsThe other common form of pink eye is due to allergens or foreign bodies in the eye. For anybody with pollen allergies, this is nothing new. In this form conjunctivitis may cause extra tearing, your body’s natural attempt to dislodge foreign elements. Your doctor may prescribe medicated eye drops to help with this, or suggest eye washing procedures. This is not a contagious form of conjunctivitis.

Anybody can get pink eye, but newborns and children are the most common patients. Also people who wear contacts are more likely to get pink eye due to a improper cleaning of lenses or lenses that have been worn for too long. Some people with sensitive eyes may choose to uses a lens case that cleans and disinfects the lenses at night to prevent pink eye. It is always important to talk to your optometrist about pink eye to ensure that it is not just a symptom of a more serious eye condition.

We are available for a consultation. Please contact us today.

Contact us by phone or email… or visit our office today!

 

Sources:

AllAboutVision.com

A Handbook of the Diseases of the Eye and Their Treatment – Swanzy, Henry Rosborough

Manual of the Diseases of the Eye – May, Charles Henry

EyeCareSource.com

WebMD.com

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Cataract

A cataract is when the lens of the eye gets cloudy. It usually happens as we age, as the protein in the lens starts to clump and therefore lose its transparency. The lens has several layers and a cataract can occur in any of those layers. Your optometrist will diagnose a cataract and characterize it by the layer of the lens affected, nuclear, cortical, or subcapsular. There is no identified cause of cataracts up until this point, but correlations have been found between exposure to radiation, UV rays, diabetes, steroids and certain other drugs, or possible even pollution of the air and alcohol. These are statistical correlations, however, and do not provide explanations.

To fully correct a cataract the only option is to remove the lens surgically. This should be considered once the cataract has progressed to the point of serious vision impairment. Up until that point, new and stronger prescriptions can relieve some of the problems, as well as using outside sources like a magnification tool or a certain kind of lighting. Cataract surgery is highly successful in repairing vision once the cataract has progressed to that point.

Sources:
Swanzy, Henry Rosborough. A handbook of the diseases of the eye and their treatment.

Cataracts

American Optometric Association

ANOMALIES OF THE ACCOMMODATION – CLINICALLY CONSIDERED

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Correction & Laser Surgery

Today’s technology allows for many alternatives to correcting refractive errors than simply wearing glasses. Patients with myopia, hyperopia, astigmatism, presbyopia, and even keratoconus have more options than ever to maximize their vision. Where glasses and contact lenses are certainly the most common means of vision correction, there are many other options that may apply.

LASIK (Lasar Assisted in Situ Keratomileusis)

Lasik surgery, sometimes called refractive surgery or laser vision correction, has become the most popular and most frequently performed elective surgery in North America. Laser surgery is used to correct the most common refractive errors including myopia, hyperopia, and astigmatism.

How Lasik works

Lasik procedures are conducted by ophthalmologists, medical doctors who specialize in surgery of the eye. The surgeon will create a protective flap to access the inner corneal tissue. Once the tissue is able to be accessed, the inner layers of the cornea are reshaped by computer controlled pulses of laser light. The reshaping of the cornea improves, and often eliminates the need of a corrective prescription. Once the tissue is reshaped, the surgeon replaces and aligns the flap to its original position.

Lasik procedures are not correct for everyone, but there are several different types that may better suit a patients needs. Custom Lasik is the most popular and desirable Lasik procedure. By using Wavefront Technology, the specific manner of which light travels is detected and mapped. This technology provides information about the specific characterizations of your eye. This data can then be used by your surgeon to increase your success rate and enables optimal results.

Bladeless Lasik offers a full customization of all aspects of your Lasik procedure, including creating a custom flap during procedure in order to provide optimal results.

LASEK (Laser Assisted in-Situ Epithelial Keratomileusis)

Sometimes referred to as epi-LASEK, this procedure is ideal for candidates who had previously been turned down for Lasik procedures due to thin or irregular corneas.

How Lasek Works

During a LASEK procedure, your surgeon will remove the top layer of the cornea as a flap-like (or epithelial) sheet before reshaping the inner tissue of the cornea with computer controlled lasers. The flap is then replaced and the patient is given soft contacts after the procedure in order to protect the cornea. LASEK differs from LASIK by means of procedure. In a normal Lasik surgery, a flap is created by the surgeon using a microkeratome. In Lasek, the flap is created by loosening the tissue covering the cornea and allowing it to heal after the procedure.

PRK (Photorefractive Keratectomy)

PRK is an elective surgery to corrective for refractive errors. Previous to the development of Lasik, PRK was the most popular option for vision correction. PRK surgery involves reshaping the surface curvature of the eye to improve or eliminate the need for prescriptions. PRK is ideal for patients with thinner corneas or with vocational or sports-related limitations where the corneal flap is contraindicated.

How PRK Works

PRK differs from Lasik in that the surgeon does not create a flap. Custom PRK uses Wavefront Technology to map aberrations in the eye and allows the surgeon most data to make PRK successful. PRK surgery is preformed with no incisions; instead a calibrated laser removes the epithelium layer and allows the surgeon to access the inner tissue of the cornea. Once that tissue is accessible, the lasers will reshape the curvature of the eye. Deeper layers of the cornea remain untouched and the epithelium layer will regrow in about 5 days.

Healing time from PRK procedures tends to be slower than with Lasik, and can cause some discomfort and vision impairment while healing.

CK (Conductive Keratoplasty)

Conductive Keratoplasty is a procedure using radiofrequency (RF) energy to reshape the cornea. CK is ideal for patients with presbyopia or farsightedness over the age of 40. CK procedures can improve your near vision, allowing you to decrease your dependency on reading glasses.

How CK Works

CK works by reshaping the surface of the eye, changing how light is focused. By shrinking corneal tissue with controlled release of RF energy, light is redirected to the retina. This reshaping technique steepens the cornea and allows for the correction of near vision. This RF energy is released in the form of a tiny probe that circles around the cornea to shrink small areas of corneal tissue.

Implantable Collomer Lenses (ICL) and Phakic Intraocular Lenses (IOL)

Ideal for patients who have very high prescriptions that are not able to be corrected with refractive surgery, ICLs are implantable contact lenses that are surgically implanted into the eye and allows for additional focusing power without removing any tissue. Unlike cataract surgery, the natural lens is preserved. ICL offers permanent vision correction.

Intraocular Lens (IOLs) are implanted after refractive lensectomy (removal of the natural lens) in order to correct for many prescriptions that are not able to be corrected with other refractive surgeries. Phakic IOLs are inserted in the eye and allow light to be directed properly onto the retina. An incision is made onto the eye, and the Phakic IOL is placed directly behind the iris.

Vision Correction – Non Surgical

Orthokeratology

Orthokeratology (ortho-k) is a non-surgical procedure that can reverse the effects of nearsightedness on your vision. Basically, your eye doctor fits your eyes for special contacts made to exactly balance the specific error in your vision. By using a special machine, your eye doctor will “map” the surface of the cornea and use that data to fit you for a type of contact called a gas permeable lens. These lenses are harder, more rigid, and made out of a material that allows more oxygen to pass through the lens to the eye than the average soft lens. The rigidity of the lens is what makes this procedure more permanent than the normal contact lens fitting. The harder lenses actually alter the shape of the cornea, for a limited amount of time, so that you can actually go without them and still be able to see clearly. The procedure is done slowly, with incremental adjustments of the prescription, until the shape of the cornea is more like a normal, healthy eye, and contacts are no longer necessary. It is important to wear them frequently, however, because the reshaping of the eyes is temporary. They will revert back to the irregular shape that causes less-than-perfect vision if you are not diligent about wearing your lenses.

Generally, vision is improved and clear for about a day without the lenses, and after that the eyes will need to be re-shaped. New technological findings in the realm of contact lenses have made it possible for gas permeable lenses to be suitable for overnight wear, so ortho-k has surged in popularity as of late. Patients are now able to wear their contacts while they are sleeping and remove them during waking hours, living unbothered by some of the inconveniences of contact lenses.

The ideal candidate for ortho-k is a nearsighted person with a refractive error of less than -4 or -5, and little to no astigmatism. This procedure is not probably adequate for someone who wants to eliminate contacts altogether—he or she may be looking for LASIK surgery—but it is great for someone who cannot or is unwilling to pay for LASIK, but would like to achieve some of the benefits of lens-free vision.

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Pediatric Eye Care

Vision Care Near Boston for the Whole Family:

Children’s Eye Exams Should Be Scheduled Regularly

Regular eye exams are a crucial component of health care in young children that often is not given the attention it demands. Most children will have healthy and normal-functioning eyes, but there is always a risk for eye disease or damage, most of which are more easily treatable in children than in adults, which is why annual pediatric eye exams are so important.

Kid Friendly Eye Doctors that Specialize in Family Eye Care

Children have vision needs that go beyond simply ‘needing glasses.’ Our optometrists are trained to detect, diagnose, and treat many complications that can occur as a child’s eye matures. Additionally, our eye exams are specifically catered to children. Our experienced, caring doctors and staff strive to create a kid-friendly atmosphere and carry a full line of frames for infants, children, and young adults.

Regular eye exams are a crucial component of health care in young children that often is not given the attention it demands. Most children will have healthy and normal-functioning eyes, but there is always a risk for eye disease or damage, most of which are more easily treatable in children than in adults, which is why pediatric eye exams are so important.

Newborns will undergo an eye examination by the family doctor or pediatrician within the first few days of birth, and most congenital eye conditions will be identifiable then. Most children will not fall into this category, but that does not mean that future eye exams are not necessary. As time passes, your child’s eyes will become stronger and more aligned, and the infant will learn to focus on objects, lights, and sounds and follow their movement around them. All of these milestones will be progressing within the first six months of life.

Schedule a Comprehensive Eye Exam for Infants at 6 Months

At six months it is recommended that every child be scheduled for a comprehensive eye exam with an optometrist or ophthalmologist, separate from a scheduled check-up at the pediatrician’s office. These professionals have equipment and training specifically for eye care that can make a difference in your child’s life, and so this appointment is an important juncture for your child’s health and development. Significant issues are not common, but identifying them early will make curing and treating them most successful. In a separate section of this article we will discuss the most common pediatric eye conditions, their implications and treatments.

Schedule Comprehensive Eye Exams for Kids Every Two Years

If at 6 months the child’s eyes appear to be developing normally that does not mean that your child will not require eye care or examination later on. It is recommended that even children with no diagnosed eye conditions get a full eye exam every two years to track progress and development. Definitely before entering kindergarten, around five years old, each child should have an assessment. This is because good vision is so intrinsically associated with school success, and identifying a problem in your child’s vision as he or she enters school will ensure that difficulties in school do not arise out of an eye-related issue, especially if treatment was possible.

What Is Done During an Eye Exam for Children?

Babies have developed vision by three or four months of age, and so testing can begin then for the basic vision functions. Generally at the six month eye exam an optometrist will test for three things: pupil response, fixate and follow, and preferential looking. The test for pupil response is to see if the child’s pupils dilate and shrink appropriately when introduced to different levels of light. By the time a child is three months old he or she should be able to focus on an object and follow its movement, which an eye doctor will test for to ensure that the eyes are strong and working together. Preferential looking tests the normal reactions and functions of the eyes, using blank cards and patterned cards to attract the child’s eyes to the patterns. If any of these tests appear abnormal, it may be a sign that further examination and treatment is necessary.

At this six month appointment it is also already possible to test your child’s visual acuity (the standard test that adults do with letter charts to test clearness of vision), as well as determine if he or she has nearsightedness, farsightedness, or astigmatism.

Parent Tips for Eye Care For Children

To make sure that you get the most out of your kid’s eye Doctor appointments, be prepared with information regarding your child’s health history, including birth information (weight, whether or not they were born at full term, etc.). All of this information will be important for your doctor’s assessment of your child, and having it on hand will expedite the process and make your time with the doctor more valuable. It is also helpful to choose a time of day when your child is generally alert and active and happy.

Common Child Eye Conditions Symptoms and Treatment

Strabismus

What are the Symptoms of Strabismus in Children

Strabismus is a condition where the eyes do not look together at the same object. One may appear to be pointing up, down, or to the side while the other is focused correctly. This is a physical condition that can occur in adults as well as children, and it is not to be confused with the normal development of infant eyes. It is normal for new infants to appear “cross-eyed” or to notice in general that their eyes do not always appear to be in sync. Their neurological system and muscles are developing, and should get stronger over time. By six months, however, if you are noticing that consistently their eyes do not appear to be working as a team, then that is a sign that your child may have strabismus.

Treatment Options of Strabismus in Children

There are many ways to treat strabismus, and treatment generally depends on the severity of the condition, one of the reasons that identifying the problem early on is so beneficial. Often eye exercises and/or a patch will help to strengthen the weaker eye and get them working together again. If this does not work, then eye drops or possibly corrective surgery may be necessary. It is important to get strabismus treated because it can lead to the vision condition amblyopia (‘lazy eye’), and also because good vision is associated with higher motor skills and quicker development in other areas of growth.

Amblyopia

Diagnosing and Treating Amblyopia in Children

Amblyopia is the vision condition that can occur from the physical condition of strabismus. It can also be caused by severe near-or far-sightedness, as well as trauma to the eye. Technically, the affected eye is called amblyopic, meaning that central vision in that eye has been lost.

Treatment Options for Children with Amblyopia

The most common practice for treating amblyopia is eye patching. The stronger eye may be patched for several hours a day or even all day as a means of strengthening the muscles around the weaker eye. Eye drops may also be used in the stronger eye to cause blurring, for the same effect. Surgery may be required for more severe cases, and it has been seen to be highly successful. Whatever the method, it is important to get amblyopia treated because it can lead to later vision problems and poor depth perception.

Early treatment is key, because while a child’s brain is developing there is still time to correct the problem permanently. After about age 9, that is much less likely, and the patient will have poor vision for life.

School Eye Screenings for Kids are Not Thorough Enough

Most states mandate an in-school vision screening for all children, and many parents get the impression that this screening is adequate examination of their child’s eyes and do not therefore take their children to an eye care practitioner to get a comprehensive exam. Truthfully, the school exams simply do not test for all of the important variables in vision, and many conditions could therefore go undiagnosed. The school screenings generally just test distance-acuity, and leave out the near-vision tests for sight within an arm’s length. This occurs even though most of the work a child does in school is at these close distances, such as reading and writing. This can directly affect a child’s performance in school, and often vision problems can go misdiagnosed because they have not been tested for. While the school screenings are important and useful, they are no replacement for the bi-annual exams that all children should have.

Eyewear for Children

Eye Glasses and Contact Lenses for Kids

Young children diagnosed with nearsightedness or farsightedness will need to be fitted for corrective eyewear, not an easy task.

Eyeglasses for Kids: Children of course focus on the “look” of the glasses, and want something similar to parents, older siblings, or other role models, while parents are often concerned about durability and wear-and-tear. Many advances have been made to accommodate both points of view. Now there are lines of children’s glasses that are effectively just smaller versions of adult frames, made with polycarbonate lenses and stainless steel or titanium frames that won’t break easily. Kids’ glasses also often feature spring hinges, which allow the temples to be extended in both directions, because children often overextend the frames outward when taking off or putting on their glasses.

Contacts for Kids: Although it may surprise some, many children are ideal customers of contact lenses, as early as 8-10. Kids often ask for them because they feel they will make them look better, and parents can be receptive to these requests, considering their child’s individual behaviors to see whether or not he or she is ready for the responsibility of contacts. If the child performs well at chores and responsibilities around the house and does not need constant reminders to do daily tasks, then he or she might do best with contacts. Often children are much more concerned with following directions and paying attention to details, and so take better care to do exactly what the instructions tell them to, making them better lens wearers than adults who like to cut corners. Most children should start with daily disposable lenses, since those do not require upkeep.

Contacts for Active Kids

Contact lenses are also very useful for children who are engaged in activities like sports and dance, things that can be difficult to do with eyeglasses on, or may even be dangerous.

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Eye Lumps and Bumps

Diagnosing and Treating Eyelid and EyeBall Lumps and Bumps

One of the more common eye problems bringing patients to our office is lumps or bumps under the eyelid. The lump can be either painful or not painful, a red bump, or a clear bump on the eyeball itself. Bumps on the eyeball under the lid can appear suddenly or grow slowly. A bump on the eyeball or under the eyelid can be from several causes but to diagnose it properly a patient should call the office and schedule an appointment with the Optometrist to have it examined. On occasion, the bump on the eyelid will resolve on its own with warm compresses but it is important to have it examined by one of our Cambridge eye doctors to make sure eye drops are not needed.

Giant Papillary Conjunctivitis – Hard Bumps or Lumps under the Eyelid

If there are many hard bumps or lumps under the upper and lower eyelid and the diagnosis is Giant Papillary Conjunctivitis when the patient is a contact lens wearer, several eye drops are helpful in clearing the bumps. The bumps or lumps are more often under the upper eyelid. Additional symptoms the patient will experience is contact lens intolerance, foreign body sensation even more pronounced when not wearing contact lenses, and when initially taking out contact lenses at the end of the day. Patients may also experience pain when closing their eyes especially when not wearing contact lenses. Patients will feel less pain and discomfort while the contact lenses are in their eyes. And the pain is often more pronounced immediately after taking out lenses at the end of the day. The reason the pain occurs when not wearing contact lenses is the contact lens serves as a barrier to the cornea or eye. Once properly diagnosed by our Optometrists, eye drops will be prescribed that are most effective in relieving the symptoms and allowing contact lens wearers to resume contact lens wear. The most effective type of eye drops cannot be purchased over the counter. Also, in some cases patients will be advised to discontinue wearing contact lenses for a certain period of time to allow the eyes to heal. In addition, the patient may need to revise their contact lens schedule permanently or just for a period of time. It is also recommended that patients change their contact lens type to daily contact lenses instead of bi-weekly or monthly lenses. It is very important for contact lens wearers to have regular and yearly appointments with their Optometrist to check for the development of contact lens related issues before they arise.

Eyelid Stye – Hard, Red or Clear Bump on the edge of the Eyelid

Another lump or bump that appears on the edge of the eyelid is called a Stye. It appears as a hard, red or clear bump on the edge of the eyelid. Sometimes the bump can grow large and be quite painful. A Stye sometimes has a pus point in which fluid will drain. Only in rare cases can a Stye be sight threatening, but larger, hard bumps on the eyelid can induce astigmatism and affect vision. In this case, we would recommend having it removed by one of our associated Surgeons. If the bump is diagnosed as a Stye, it is common for Optometrists to recommend applying warm compresses to the eye bump because the compresses help to quicken the healing process. At Harvard Square Eye Care the Optometrists can determine the correct course of action. The hard lump on the eyelid or eyeball may need topical antibiotics to prevent an infection in the eye from developing. It is important to schedule an appointment with an Optometrist at one of our locations to diagnose and prescribe the proper medication.

Chalazion – Hard Lump on the Eyelid

The Stye can sometimes resist resolving completely and turn into a hard lump on the eyelid. If this occurs the name is a Chalazion. It is recommended to digitally rub the hard bump often to attempt to loosen the coalesced material that makes up the lump on the eyeball. A larger Chalazion can affect vision because it can put pressure on the cornea and cause Astigmatism. In some cases the hard bump needs to be removed by one of our associated surgeons.

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Hyperopia

The most common vision condition is hyperopia or hypermetropia, generally known as farsightedness. Those with hyperopia have trouble doing close work like reading or sewing and need to squint to see objects right in front of them.

This is all because hyperopes have eyes that are slightly shorter than average, which means that when light is refracted through the lens it is focused onto a point behind the retina instead of onto the retina itself. People often confuse hyperopia with myopia (nearsighted vision) but they are in fact the opposite.

The first solution to the problem of hyperopia is, of course, glasses or contact lenses. Depending on the severity of the diagnosis, glasses may be prescribed for wear all the time or sometimes only when doing things like reading or driving.

Farsighted Vision is Treatable

There are now also refractive surgery options available such as LASIK surgery, PRK (photorefractive kerectomy), and conductive keratoplasty. All of these options are surgical procedures that reshape the cornea to fix the hyperopia and make the proportions right again, redirecting the light rays onto the retina.

The only difference is that LASIK involves removing corneal cells underneath a flap, while PRK involves removing from the surface of the cornea, and CK does not remove any cells at all, but rather uses radiowaves to reshape the curvature of the eye. Your Ophamologist will study your particular case to decide which option will best serve your needs.

Sources:

  • Ophthalmic Diseases and Therapeutics – Norton, Arthur Brigham
  • American Optometric Association
  • AllAboutVision.com
  • EyeCareSource.com
  • Hyperopia and Presbyopia – Tsubota, Kazuo
  • A Manual of the Diagnosis and Treatment of the Diseases of the Eye – Jackson, Edward
  • DocShop.com
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Myopia

A highly common vision condition is myopia, or nearsightedness. People diagnosed with myopia generally have difficulty seeing into the distance, which makes daily tasks like driving or watching a presentation or TV very taxing. In a normal eye rays of light are bent and reflected from the lens onto a single point on the retina, and it is this reflection that produces the image our brain interprets as sight.

In order for this to work the light has to be bent a certain way to make sure that the light focuses on the correct part of the retina. With myopia, the math is thrown off and the light rays do not project the image onto the retina, but rather to a point in front of the retina. The easiest explanation for this is that the myopic eye is somehow longer than the normal eye, which changes the relationship between the lens, the retina, and the light that is reflecting the image.

It was previously assumed that myopia was a hereditary condition, but recent research also cites other possible causes such as too much eye strain or close work. There is still a great deal of study to be done. To learn more about your vision visit our How The Eye Works page.

Myopia Treatment

There is a range of treatment options for myopia depending on lifestyle choices as well as the severity of the impairment. Glasses and contact lenses are the most common solution, though refractive laser surgery has increased in popularity. One of the procedures is LASIK, in which corneal tissue is removed to reduce the length of the eye. LASIK is different from some other laser procedures because the corneal tissue removed comes from underneath rather than from the surface of the cornea.

Only certain myopia cases are suitable for the surgery. There are some other controversial options like orthokeratology and corneal refractive therapy, which involves wearing specially shaped contact lenses that can temporarily reshape the cornea. Finally, phakic IOLs, a new surgical procedure for extreme myopic cases, are an option that consists of a permanent implantable lens that helps to correct nearsightedness.

Sources:

  • AccessScience.com
  • The Eye and Visual Nervous System: Anatomy, Physiology and Toxicology – Connie S. McCaa Environmental Health Perspectives (NIEHS)
  • Refractive Surgery Center
  • Eye Studies; a Series of Lessons on Vision and Visual Tests – Johnston, J. Milton
  • The Myopia Myth – Rehm, Donald S
  • AllAboutVision.com
  • American Optometric Association
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Astigmatism

Astigmatism is another highly common vision impairment, and it often occurs along with nearsightedness or farsightedness. Like those two conditions, astigmatism is an issue of the shape of the cornea and the effect that has on the way light is refracted through to the retina.

Astigmatic corneas are oblong, longer in one direction than the other, and this causes light rays to be brought into focus at different times instead of at the same time, causing a blurring of vision.
Astigmatism Correction

You may have astigmatism if a corrective prescription of glasses does not provide the sought-after clarity that was expected. Luckily there are simple and easy ways to correct astigmatism, such as with a new prescription of glasses or contacts, or perhaps even laser surgery.

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