Helpful information from one of the Top Eye Centers of Florida


Eye allergies are no different than allergies that affect your sinuses, nose or lungs. When an allergen comes in contact with your eyes, your body releases histamine – a chemical produced in reaction to a substance that the immune system can’t tolerate. Special cells called mast cells make histamine. These cells are present throughout the body but are highly concentrated in the eyes.

Ocular allergens tend to be airborne (as are most other allergens). The most frequent allergic triggers include: Pollen; pet hair or dander; dust; some medicines.

When ocular allergies can’t be controlled, there are several medications that may help relieve symptoms. Most of these treatments come in a topical form – such as eye drops or an ointment.

Eye drops can help in two ways: (1) by physically washing away allergens; and (2) by moistening the eye, which can become dry and red when irritated. Eye drops that contain medications to help reduce allergy symptoms also are available.

Some tips for controlling allergies: Try to avoid being outside when the pollen count is particularly high (check your local paper or the Internet.) Keep doors and windows shut to keep pollen out; use air filters indoors, and have someone vacuum regularly; try not to rub your eyes-this can make irritation worse and increases risk of infection; over-the-counter medications such as antihistamines, nasal sprays and eye drops can help; if your allergies are severe or home remedies don’t help, consult your physician.

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Amblyopia (Lazy Eye)

Amblyopia is poor vision in an eye that did not develop normal sight during early childhood. It is sometimes called “lazy eye.”

When one eye develops good vision while the other does not, the eye with poorer vision is called amblyopic. Usually, only one eye is affected by amblyopia.

Amblyopia is detected by finding a difference in vision between the two eyes. Since it is difficult to measure vision in young children, your ophthalmologist often estimates visual acuity by watching how well a baby follows objects with one eye when the other eye is covered.

The condition is common, affecting approximately two or three out of every 100 people. The best time to correct amblyopia is during infancy or early childhood.

To correct amblyopia, a child must be made to use the weak eye. This is usually done by patching or covering the strong eye, often for weeks or months.

It is recommended that all children have their vision checked by their pediatrician, family physician, or ophthalmologist (Eye M.D.) at or before their fourth birthday.

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Aniridia means “without iris.” It is an eye condition characterized by the absence or partial absence of the iris muscle tissue. The iris, which is a disk of muscle suspended behind the cornea, regulates the amount of light entering the eye by adjusting the size of the pupil. A greater than normal amount of light enters the eye of patients with aniridia. This can result in reduced vision.

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Anterior chamber

The space in the eye that is behind the cornea and in front of the iris.

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In an astigmatic eye, the surface of the eye is shaped like an oval more than a round sphere. The oval shape causes blurriness. The amount of astigmatism is measured in the second notation of the prescription. Astigmatism often accompanies myopia and hyperopia.

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Blepharitis is a chronic or long-term inflammation of the eyelids and eyelashes. It affects people of all ages. Among the most common causes of blepharitis are poor eyelid hygiene; excessive oil produced by the glands in the eyelid; a bacterial infection (often staphylococcal); or an allergic reaction.

Seborrheic blepharitis is often associated with dandruff of the scalp or skin conditions like acne. It can appear as greasy flakes or scales around the base of the eyelashes and a mild redness of the eyelid. It may also result in a roughness of the normally smooth tissue that lines the inside of the eyelid.

Ulcerative blepharitis is less common, but more serious. It is characterized by matted, hard crusts around the eyelashes, which when removed, leave small sores that ooze or bleed. There may also be a loss of eyelashes, distortion of the front edges of the eyelids and chronic tearing. In severe cases, the cornea, the transparent front covering of the eyeball, may also become inflamed.

In many cases, good eyelid hygiene and a regular cleaning routine may control blepharitis. This includes frequent scalp and face washing; warm soaks of the eyelids; and eyelid scrubs. In cases where bacterial infection is a cause, eyelid hygiene may be combined with various antibiotics and other medications. Eyelid hygiene is especially important upon awakening because debris can build up during sleep.

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A cataract is a clouding of the normally clear lens of the eye. This happens to everyone as we age. Common symptoms of cataracts include: painless blurring of vision; glare light sensitivity; poor night vision; double vision in one eye; needing brighter light to read; fading or yellowing of colors.

How quickly a cataract develops varies among individuals, and may even be different between the two eyes. Most age-related cataracts progress gradually over a period of year, average age people come to have surgery is 74 years old. Other cataracts, especially in younger people and people with diabetes, may progress rapidly over a short time. It is not possible to predict exactly how fast cataracts will develop in any given person.

Surgery is the only way a cataract can be removed. However, if symptoms of cataract are not bothering you very much, surgery may not be needed. Sometimes a simple change in your eyeglass prescription may be helpful. Surgery should be considered when cataracts cause enough loss of vision to interfere with your daily activities, such as driving at night or in bright sunlight.

There are no medications, dietary supplements or exercises that have been shown to prevent or cure cataracts.

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Conjunctivitis, also known as “pink eye,” is an inflammation of the conjunctiva (the membrane lining under the eyelids) and can be caused by allergies or infections. Both have similar symptoms, such as redness, itching and swelling in the eye area. However, when conjunctivitis is caused by allergies, both eyes are usually affected. Viral or bacterial conjunctivitis can affect either a single eye or both eyes. It is important to pinpoint whether someone has conjunctivitis because of allergies or infection since each condition has a different treatment.

Common symptoms of allergic conjunctivitis are: Redness and itching under the eyelid; excessive watering; swelling of the eyeball

Common symptoms of conjunctivitis associated with infection are: Feeling that eyelids are glued shut upon waking; sensitivity to light; pus on the surface of the eye; burning sensation.

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The clear front window of the eye that transmits and focuses light into the eye.

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Corneal Disease (Keratitis)

Keratitis is a deep infection of the cornea caused by the presence of bacteria in the cornea. The condition may cause severe pain, reduce vision, and produce a corneal discharge. Minor corneal infections can be treated with eye drops. Serious infections require more intensive treatment to eliminate the infection and reduce inflammation.

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Corneal Ulcer

A corneal ulcer can be very painful. Ulcers are caused when the corneal tissue is eroded or rubbed away. The most common source is due to improper contact lens use. Treatment will be specific or the severity of the condition. Prompt evaluation is required for proper treatment.

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Your correction or prescription is the actual lens power within your glasses or contact lenses. It is the slip of paper that your eye doctor gives to you for your glasses to be made. Every prescription is different and unique for each person’s eyes. That is why each surgery has to be tailor made to each specific patient.

For example: (-4.00 +2.00 x 180). The first number, -4.00, indicates four diopters of nearsightedness. The second number, +2.00, indicates two diopters of astigmatism oriented at 180 degrees. Astigmatism means that your eyeball is shaped more like an oval than a round circle, and therefore, the oval is pointing at the 180 axis. Your correction/prescription is the most important number for the surgeon. These are the numbers used to decide what type of surgery is best for you and the actual numbers needed to program into the laser.

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Crystalline lens

A transparent, colorless body located in the front third of the eyeball, behind the iris, that helps bring rays of light to a focus on the retina.

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Diabetic Retinopathy

If you have diabetes, your body does not use and store sugar properly. High blood-sugar levels can damage blood vessels in the retina, the nerve layer at the back of the eye that senses light and helps to send images to the brain. The damage to retinal vessels is referred to as diabetic retinopathy.

There are two types of diabetic retinopathy: nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR).

NPDR, is an early stage of diabetic retinopathy. In this stage, tiny blood vessels within the retina leak blood or fluid. The leaking fluid causes the retina to swell or to form deposits called exudates.

PDR is present when abnormal new vessels (neovascularization) begin growing on the surface of the retina or optic nerve. The main cause of PDR is widespread closure of retinal blood vessels, preventing adequate blood flow. The retina responds by growing new blood vessels in an attempt to supply blood to the area where the original vessels closed. PDR may cause more severe vision loss than NPDR because it can affect both central and peripheral vision.

The best treatment is to prevent the development of retinopathy as much as possible. Strict control of your blood sugar will significantly reduce the long-term risk of vision loss from diabetic retinopathy. If you have diabetes, it is important to know that today, with improved methods of diagnosis and treatment, only a small percentage of people who develop retinopathy have serious vision problems. Early detection of diabetic retinopathy is the best protection against loss of vision.

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Unit of measurement for optical strength or refractive power of glasses or contact lenses.

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Dry Eye Syndrome

Some people do not produce enough tears or the appropriate quality of tears to keep the eye healthy and comfortable. This is known as dry eye.

Tears are produced by two different methods. One method produces tears at a slow, steady rate and is responsible for normal eye lubrication. The other method produces large quantities of tears in response to eye irritation or emotions.

Tears that lubricate are constantly produced by a healthy eye. Excessive tearing occurs when the eye is irritated by a foreign body, dryness or when a person cries.

The usual symptoms of dry eye include: stinging or burning eyes; scratchiness; stringy mucus in or around the eyes; excessive eye irritation from smoke or wind; excess tearing; difficulty wearing contact lenses; decreased ability to read for an extended period of time.

Excess tearing from “dry eye” sounds illogical, but if the tears responsible for maintenance lubrication do not keep the eye wet enough, the eye becomes irritated. When the eye is irritated, the lacrimal gland produces a large volume of tears that overwhelm the tear drainage system. These excess tears then overflow from your eye.

Dry eye is often caused by the normal decrease in tear production as we age. Although dry eye can occur in both men and women at any age, women are most often affected. This is especially true after menopause.

Dry eye is often treated by using eyedrops called artificial tears. They lubricate the eyes and help maintain moisture. Artificial tears are available without a prescription. There are many brands on the market, so you may want to try several to find the one you like best. You can use the tears as often as necessary – once or twice a day or as often as several times an hour.

With extreme cases of dry eye, your ophthalmologist may recommend temporarily or permanently closing the small channels that drain tears away. The closure conserves your own tears and makes artificial tears last longer.

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Endothelial cells

Refers to the cells that make up the thin, innermost layer of the cornea. Endothelial cells are essential in keeping the cornea clear.

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Flashes and Floaters

Floaters and flashes are small, transparent or cloudy specks within the vitreous, the clear, jelly-like fluid that fills the inside of your eyes. They appear as specks of various shapes and sizes, threadlike strands or cobwebs. Since they are within your eyes, they move as your eyes move and seem to dart away when you try to look at them directly. Most spots are not harmful and rarely limit vision.

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The central point on the retina that produces the sharpest vision.

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Fuchs’ Dystrophy

Fuchs’ Dystrophy is a slowly progressing disease of the endothelium (the innermost layer of the cornea). This hereditary disease causes corneal swelling, which clouds the cornea, and decreases eye function. Treatment may begin with ointments or drops to reduce the swelling. In more severe cases, corneal transplants are performed to restore vision.

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Glaucoma is an eye disease in which the internal pressure of the eye increases enough to damage the nerve fibers in the optic nerve and cause vision loss. The increase in pressure happens when the passages that normally allow fluid in the eyes to drain become clogged or blocked.

Glaucoma is one of the leading causes of blindness in the U.S. It most often occurs in people over age 40. People with a family history of glaucoma, African Americans, and those who are very nearsighted or diabetic are at a higher risk of developing the disease.

The most common type of glaucoma develops gradually and painlessly, without symptoms. As the disease progresses, a person with glaucoma may notice his or her vision gradually failing with: blurred vision; loss of peripheral vision; difficulty focusing on objects; presence of halos around lights.

Glaucoma cannot be prevented, but if diagnosed and treated early, it can be controlled. The treatment for glaucoma includes prescription eye drops and medicines to lower the pressure in your eyes. In some cases, laser treatment or surgery may be effective in reducing pressure.

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Hazy ring around bright lights seen by some patients with refractive error or optical defects (e.g., cataracts or corneal swelling).

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Herpes Zoster (Shingles)

Shingles are an infection caused by the chicken pox virus. After an initial outbreak of chicken pox, the virus remains dormant within the nerve cells of the central nervous system. In some cases, sometimes years later, the virus will reactivate in the eye. This can cause painful blisters on the skin and the eye. Treatment may reduce inflammation and scarring in the cornea when the skin around the eye is affected.

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Hordeolum (Stye)

A stye is a red, painful, swollen bump on the eyelid. Lid hygiene, warm compresses and artificial tears are recommended to prompt healing. Occasionally, oral antibiotics may be helpful.

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An eyeball, which is too short or a cornea with too little curvature, focuses light behind the retina. Distant objects are clear and close object are blurred. Your prescription would show a plus sign in front of the first number if you are farsighted (+3.00 +1.00 x 90).

Many people confuse a condition called presbyopia with hyperopia. They are not the same. Presbyopia occurs when eyes gradually lose the ability to focus on near objects. This occurs during the natural aging process of the lens inside the eye. Most people notice this change around age 40 and begin to use reading glasses and bifocals.

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This technique actually uses two lasers to perform the procedure. Instead of using a mechanical microkeratome to create the flap, IntraLASIK uses a femtosecond (FS) pulsed laser to create the corneal flap. The corneal flap is created with the IntraLase FS. The flap is then lifted and an Excimer laser is used to perform the actual vision correction.

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Intraocular contact lens

A small synthetic lens implanted into the eye without removing the crystalline lens.

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Intraocular lens

A small synthetic lens, made of a hard plastic (polymethyl methacrylate or PMMA), silicone, acrylic, or hydrogel material implanted into an eye after cataract surgery to replace crystalline lens, which has been removed.

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Intraocular Pressure (IOP)

Pressure caused by the fluid inside the eye; it helps to maintain the shape of the eye.

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Circular, colored portion of the eye. Its opening forms the pupil. The iris helps regulate the amount of light that enters the eye.

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Iritis is an inflammation of the iris, or colored part of the eye. This causes the eye to be red, painful and sensitive to light. Medical treatment is necessary to decrease pain and to prevent additional eye damage.

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Keratoconus is a vision disorder that occurs when the normally round cornea (the front part of the eye) becomes thin and irregular shaped. This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision.

Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness and astigmatism that is caused by the early stages for keratoconus. As the disorder progresses and cornea continues to thin and change shape, rigid gas permeable contact lenses can be prescribed to correct vision adequately. In most cases, this is adequate. The contact lenses must be carefully fitted and frequent checkups and lens changes may be needed to achieve and maintain good vision.

In a few cases, a corneal transplant is necessary. However, even after a corneal transplant, eyeglasses or contact lenses are often still needed to correct vision.

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Macular Degeneration

Macular degeneration is a deterioration or breakdown of the macula. The macula is a small area in the retina at the back of the eye that allows you to see fine details clearly and perform activities such as reading and driving. When the macula does not function correctly, your central vision can be affected by blurriness, dark areas or distortion. Macular degeneration affects your ability to see near and far, and can make some activities – like threading a needle or reading – difficult or impossible.

Many older people develop macular degeneration as part of the body’s natural aging process. There are different kinds of macular problems, but the most common is age-related macular degeneration (AMD). Exactly why it develops is not known, and no treatment has been uniformly effective. Macular degeneration is the leading cause of severe vision loss in Caucasians over 65.

Macular degeneration can cause different symptoms in different people. The condition may be hardly noticeable in its early stages. Sometimes only one eye loses vision while the other eye continues to see well for many years.

But when both eyes are affected, the loss of central vision may be noticed more quickly. Some common ways vision loss is detected: words on a page look blurred; a dark or empty area appears in the center of vision; straight lines look distorted.

Certain types of macular degeneration can be treated with laser surgery, a brief outpatient procedure. Laser surgery and another form of treatment called photodynamic therapy use a focused beam of light to slow or stop leaking blood vessels that damage the macula. These procedures may preserve more sight overall, though they are not cures that restore vision to normal.

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The instrument a surgeon uses to create the corneal flap in the uppermost layer of the cornea during the LASIK procedure.

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Monofocal IOL

Provides good distance and sometimes intermediate vision but doesn’t correct near vision. Usually requires corrective lenses or eyeglasses after surgery for reading and near vision tasks.

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Multifocal IOL

Designed to provide distance and near vision simultaneously but does not restore good intermediate vision. Increased glare and halos reported at night.

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An eyeball, which is too long, or a cornea with too much curvature focuses light in front of the retina. In nearsighted or myopic eyes, the person has difficulty seeing at a distance, such as driving or seeing the black board from the back of the room. Approximately 30 to 35% of the population is nearsighted.

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A nevus is a benign lesion in the eye. This is most commonly formed on the iris or in the choroids. A nevus rarely becomes a cancerous lesions (melanomas), but if any change is noticed, an ophthalmologist should be seen for treatment.

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A pinguecula is a raised, yellowish thickening of the white part of the eye. Excessive sun exposure is a common cause. This condition is usually treated with artificial tears to decrease dryness. Sunglasses are helpful in preventing further growth.

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Posterior Chamber

The fluid-filled space between the back of the iris and resting against the capsular bag.

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Presbyopia is one of the conditions associated with the aging of the eye. After the age of 40, the muscles in our eyes lose some elasticity and cannot focus as well up close. Reading and detail work are most affected. Reading glasses or bifocals are the most common treatment. Presbyopia affects everyone as we age.

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A pterygium is a growth on the conjunctiv cornea that can cause irregular astigmatism and/or warping of the cornea. If large enough, the growth will block light entering the eye and may lead to vision loss. In severe cases, an outpatient procedure may be considered to remove the tissue. Pterygiums can be prevented by wearing UV-protective sunglasses, and applying artificial tears for surface dryness.

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Ptosis is the drooping of the upper eyelid. This condition can be slight or significant enough to impair vision. Ptosis is attributed to age, trauma, or a neurological condition. It can be repaired by surgery.

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The opening at the center of the iris of the eye that varies in diameter depending upon the brightness of the light coming into the eye.

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Refractive Surgery

Refers to many different procedures used for correcting the refractive error of an eye.

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The thin membranous lining of the rear two-thirds of the eye that converts images from the eye’s optical system into electrical impulses sent along the optic nerve for transmission to the brain.

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Retinal Detachment

A retinal detachment is a very serious condition that should receive prompt treatment. When a retinal detachment occurs, the retina pulls away from the wall of the eye, causing impairment or loss of vision. Once retinal tissue dies, the body cannot replace it.

Symptoms may include a sudden rush of many floaters, flashes of light, loss of peripheral vision or loss of central vision.

Patients should report any of these warning signs to their ophthalmologist immediately. The best chance for restoring sight relies on prompt treatment.

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Spherical aberrations

The deviation of light rays through lenses that cause images to be blurred.

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Subconjunctival Hemorrhage

A subconjunctival hemorrhage is caused when a blood vessel of the white part of the eye breaks and bleeds. It sometimes looks like an isolated reddening of the eye. Patients are encouraged to see their ophthalmologist for proper diagnosis and treatment.

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Uncorrected Visual Acuity (UCVA)

A person’s uncorrected vision refers to the vision acuity when no glasses or contact lens are used. The notation of usual acuity is written as a fraction, with normal vision being 20/20.

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Vision is measured by reading the letter chart at your eye doctor’s office. Most people identify 20/20 as perfect vision. The notation 20/20 is a scientific measurement. For example, if your vision was 20/60, this would indicate that you would have to stand 20 feet away from the chart in order to see what a person with perfect vision can see 60 feet away. The notation 20/100 or 20/400 would have the same meaning at 100 feet and 400 feet.

Everyone’s ultimate goal in having refractive surgery is to see as well without glasses (uncorrected) or contact lenses as you currently see with them. Most patients prior to surgery have uncorrected vision of 20/400 to 20/800. Their vision with glasses or contacts (best corrected vision) is 20/20 to 20/25.

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Visual Acuity

The clarity or clearness of the vision, a measure of how well a person sees. The ability to distinguish details and shapes of objects; also called central vision.

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Jump to…

I am an active woman. I travel often and enjoy running, scuba diving, water skiing, whitewater rafting and most outdoor sports. For more than 20 years, I had to endure the inconvenience of contact lenses. I was unable to wear extended wear or disposable lenses, so I always had to pack a full bag of lens cleaner, saline, sterilizing solution, Ultrazime tablets, lens cases and glasses. Every night I had to take my lenses out, clean and sterilize them. I also had to worry about losing or tearing a lens. For months I had been thinking about trying the LASIK surgery, but I wanted a doctor I felt comfortable with and trusted. I had heard stories of patients who had never even met the doctor who performed the procedure; he was just a voice behind the laser. Then I heard about Dr. Donald Barnhorst.
A friend recommended Dr. Barnhorst to me. I went in for my initial evaluation. Dr. Barnhorst examined my eyes, explained the procedure and answered all my questions. He listened to all my questions and patiently answered each one. He really put me at ease. I felt that I could ask any questions and express any concern and he would address each one, openly and honestly. I knew immediately that this was something I had to do and that Dr. Barnhorst was the doctor for me.
I wanted to proceed as soon as possible and there was an appointment available on a Thursday. I was concerned because I was scheduled to run in the Gate River Run that Saturday, and I didn’t want to miss it. Dr. Barnhorst assured me that there would be no problem. And there wasn’t! The LASIK procedure was performed as scheduled and Saturday morning I ran in the race and beat my time from the previous year.
I feel liberated. My vision is now perfect without any corrective lenses. I no longer have to carry any contact care products when I travel and no more glasses. No worry about losing or tearing a lens. I have always wanted to do the two-week rafting trip down the Colorado River, but felt I couldn’t because of my contact lenses. Now I can do anything I want and not have worry! This is the best thing I have ever done, and I have Dr. Donald Barnhorst to thank for my vision and my new-found freedom.
Thank you Dr. Barnhorst
The material contained on this site is for informational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health care provider. •© 2020 Barnhorst Eye Associates - All rights reserved. Terms of Agreement • Jacksonville Website Design Fisher Design
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