Forest Hills Vision

Nearsightedness (Myopia)

More than 70 million people in North America (about one in four) are nearsighted. Myopia is the medical term for “nearsightedness”. It occurs when your eye is too long in relation to the curvature of your cornea. Myopia causes light rays entering the eye to focus of the retina, producing a blurred image. The term “nearsighted” means that you can see objects that are “near” to you more clearly than distant objects. The more myopic you are, the more blurred distant objects appear, the higher your prescription is in diopters.

Farsightedness (Hyperopic)

Hyperopia is the medical term for “farsightedness”. Hyperopia occurs when your eye is too short in relation to the curvature of your cornea. Light rays entering your eye focus behind the retina, producing a blurred image. Some farsighted people can use their focusing muscles to pull the image forward onto the retina, allowing them to see clearly. But others, who cannot overcome the effects of severe hyperopia, need glasses for distance vision as well as reading glasses or bifocals.

Cataracts

A diagnosis of cataract means that your normally clear lens, located behind your eye’s colorful iris, has grown cloudy. The lens contains mostly water and proteins that are specially organized to focus light on the retina for clear vision. In many people, the proteins begin to clump and obscure vision. While recent scientific advances are closing in on what causes the proteins to rearrange and the lens to cloud up, we do know key risk factors for cataract formation. Growing older is one. So are long-term exposure to sunlight and smoking cigarettes. Quitting smoking and wearing protective sunglasses and a hat when outdoors can protect against cataracts. The majority of cataracts are age-related. A cataract begins as a small opacity within the lens and grows until it interferes with vision. Many people have cataracts and don’t even notice until the defect grows large. Vision might appear a little hazy at first and lights might give off a halo or glare. Colors can appear faded. Blue might look green and yellow might appear white.

Ultimately, everyday tasks become challenging. It is at this point that many people have cataract-removal surgery. According to the World Health Organization, cataracts are the leading cause of blindness in the world. In the U.S., more than half of all people 65 and older have some form of cataracts. Fortunately, when necessary cataract surgery can be very effective. The surgeon removes the clouded lens and typically replaces it with an artificial lens.

Presbyopia is part of the normal process of aging. It develops as the lens of the eye loses some of the flexibility that characterizes a younger eye. Everyone experiences the effects of presbyopia, typically between the ages of 40 and 50. Nearsighted people who become presbyopic may require bifocals in their forties, and those who never needed glasses before may require reading glasses.

Astigmatism in most cases arises from the shape of the outer layer of the eye, called the cornea. In astigmatism the curvature of the cornea is not spherical, like a basketball, but is aspherical, like the shape of a football. This irregularity leads to a distortion of vision for both near and far objects. Images are blurred as some light rays are focused and others are not. Astigmatism can occur in combination with nearsightedness or farsightedness, and is correctable with spectacles, contact lenses, or refractive surgery.

Many people experience Computer Vision Syndrome. Our eyes and brain react differently to characters on the screen than they do to printed characters. The well-defined edges and sharp contrast of printed characters make it easy for our eyes to focus. Computer screens characters, on the other hand, don't have the sharp contrast and well-defined edges, they are brighter at the center than they are on the edges. It is difficult for the human eye to focus for a long period of time on such characters, which is why our eyes tend to just drift our of focus to a resting point of accommodation.

Glaucoma is a disease where cells and fibers of the optic nerve are damaged, affecting the transmission of signals from the eye to the brain. At first there are no detectable symptoms. The brain can compensate for some visual field loss, so you may not be aware of blind areas. Eventually, vision narrows. Glaucoma can lead to blindness, but seldom does when diagnosed and treated early. Until recently, scientists believed that damage from glaucoma was solely due to increased intraocular pressure (IOP) (pressure inside the eye). Now we know that high IOP does not always cause glaucoma and it can even occur when the IOP is normal.
It is estimated that 2.2 million Americans have been diagnosed with glaucoma, and that nearly 2 million more may have the disease and not know it. Certain factors influence a person’s risk for glaucoma, including family history, diabetes, near sightedness, African American or Hispanic heritage, the use of certain medications, and age over 40. Glaucoma testing is recommended every two years for people over forty, and every year or less those at high risk or over the age of sixty.

Age related macular degeneration (AMD) is a vision disorder caused by abnormalities in a portion of the eye’s retina called the macula. Early symptoms are blurred central vision and a waviness of straight lines. The blurriness may progress to blind spots, affecting reading, TV watching and many other pleasures of independent living. Age is the single greatest risk factor for macular degeneration. Other risk factors include a family history of AMD, cigarette smoking, diet high in animal (but not fish) fat, elevated blood pressure, and high body mass index. An estimated 1.75 million Americans over the age of 40 have decreased vision from AMD . Research is advancing to understand and prevent AMD, to halt its progression, and to develop optical devices to offset vision loss.

Commonly known as lazy eye, amblyopia results from insufficient use of one eye during early childhood. This may be due to strabismus, often called crossed eyes, or ptosis, which is a dropping of the upper eyelid, or simply uneven acuity that leads the child to rely on the better performing of the two eye more heavily. It is important for amblyopia to be caught early on so as to prevent the lazy eye from becoming more functionally impared. With an early diagnosis, the eye can be treated and its vision restored.

Dry eye is a chronic medical condition that develops when the eyes tear film no longer lubricates and protects the eyes outer surface. The condition can be the result of diminished tear production or increased tear evaporation. According to researchers, increased salt concentration in the tears leads to problems with the eye surface and produces most dry eye symptoms. Patients may be able to find relief through the use of eye drops designed to restore proper tear film salt concentration or eye moisturizing drops and sprays. In more severe cases, when tear production is impaired, an inflammatory reaction may set in; further damaging cells on the surface of the eye and further suppressing tear production. Some of these patients may be able to improve tear gland function by using anti-inflammatory medicine. Dry eye can be caused by a variety of circumstances: contact lens use; smoking; exposure to hot, dry or windy climates; autoimmune diseases such as rheumatoid arthritis; thyroid conditions; menopause; increasing age; decreased blinking; the use of certain medications; and a dietary deficiency of omega-3 essential fatty acids. One of the biggest risk factors is Sjoren’s syndrome, an autoimmune disease in which the white blood cells attack the body’s own moisture-producing glands. Dry eye symptoms include: sandy-gritty irritation or burning eyes; blurred vision that clears with blinking; and discomfort from reading, TV watching or computer use. Treatments range from altering the physical environment, to artificial tears, to dietary changes, to a procedure called punctual occlusion that retains tears on the surface of the eye, to drug therapy.

An estimated 18 million American children and adults have diabetes. Within 10 years of diagnosis, 75 percent will have some degree of diabetic retinopathy. Diabetic retinopathy is caused by high blood sugar, which damages tiny blood vessels of the retina. In response, the body grows fragile new blood vessels (neovascularization0 within the retina. A person with diabetic retinopathy might notice symptoms only after damage is done. A doctor is usually able to detect retinal changes much sooner and can help prevent vision loss. Therefore, regular dilated eye exams are extremely important. Symptoms of diabetic retinopathy may include blurred vision, changes in central vision, floating spots, and even sudden vision loss. The first two symptoms are caused by swelling (edema) of the macula, the part of the retina that gives us sharp central vision. Floating spots are droplets of blood from leaky blood vessels growing into the eye’s jelly-like center (vitreous body). When these vessels bleed heavily (vitreous hemorrhage) vision may become completely blocked. Diabetic retinopathy can also cause a retinal detachment; this sometimes looks like a billowy curtain. The best approach for saving vision is prevention: Diabetic retinopathy can be delayed and often prevented through tight blood sugar control. People with diabetes can also reduce their risk of diabetic retinopathy by maintaining healthy blood pressure. Detecting and intervention of vision changes from diabetic retinopathy are best realized by scheduling annual eye examinations. Early vision loss from diabetic retinopathy may be so subtle that you don’t notice, but a doctor will.

Keratoconus is a deformation of the cornea, which loses its usual smooth curvature for a conic shape. Like nearsightedness or astigmatism this deformation prevents light rays from focusing correctly onto the retina. Keratoconus usually appears among young adults and causes slightly blurred vision and over-sensitivity to bright lights. As time goes by, the deformation worsens and vision may become more and more distorted. In the early stages, eyeglasses or soft contact lenses should be worn to rectify the visual distortion. In the later stages, it is preferable to switch to gas permeable or Hybrid contacts.