Below are brief descriptions of the various eye conditions we commonly see and treat at Lake Norman Eye Care in Mooresville.
MYOPIA (my-O-pee-ah) or Nearsightedness
The medical term for nearsightedness is myopia. When you are nearsighted, your distance vision is blurred. Close range vision is generally clear at some near distance without correction, thus the term “nearsighted.” As with most refractive errors, nearsightedness is simply caused by the shape of the eye. In this case, the eye is longer front to back, or has a steeper curve to the front lens of the eye, the cornea. Genetic, environmental or functional factors can also play a role in the development of nearsightedness.
Nearsightedness is generally corrected with eyeglasses or contact lenses. Low to moderate amounts of nearsightedness can also be corrected by reshaping the cornea with special rigid contact lenses worn only during sleep. For adults, refractive surgery such as LASIK, or lens replacements are additional options.
Presbyopia is a normal decline in close-range focusing ability of our eyes with time. Presbyopia seems to present close-range issues suddenly but actually it does not. Our eyes have maximum focusing ability in our teens, about 50% at age 40, and we gradually decline to a fixed non-variable focus around the age of 70. The average person requires a different prescription for distance vs. reading tasks around the age of 42.
Most people falsely think that muscles inside the eye weaken over time causing this gradual loss of close-range focus. To the contrary, presbyopia is a loss of elasticity of the focusing lens inside the eye. In addition, many falsely believe that if eyeglasses are worn often itwill weaken the eyes’ further. It is important to understand that wearing appropriate eyeglasses or multi-focus contact lenses full-time or part-time will not weaken or change your future visual status in any way. All humans experience this unavoidable and fully correctable visual condition.
85-90% of all eyeglass prescriptions contain some correction for astigmatism. The eye, like a camera, has an outer curved lens, the cornea, to focus light. Most commonly, astigmatism occurs when simply this front surface has more than one curvature, rather than a perfectly round shape. With astigmatism, the shape of the cornea is asymmetrical, or somewhat “egg” shaped, rather than uniformly round like a ball. As a result, an astigmatic eye requires a special two-power lens to precisely focus light uniformly.
Since astigmatism causes two different focuses per eye, and especially if astigmatism exists in both eyes, the brain has much to contend with. As a result, uncorrected or incorrect prescriptions for astigmatism cause blurred and distorted vision, as well as, annoying symptoms of eyestrain such as headaches, eye fatigue, sensitivity to light, loss of visual achievement and poor visual concentration.
It is expected that first correction or large changes in correction of astigmatism may cause objects or straight lines to appear tilted or distorted. This perception of distortion will decrease steadily with time. As with most prescriptions, it is common for the degree of astigmatism to change naturally over time. Eyeglasses, and/or, special astigmatic (toric) contact lenses are available to correct astigmatism.
Your testing has revealed a condition known as accommodative insufficiency. When our eyes look at a specific close-range target each eye must focus using a process called accommodation for that specific distance. Accommodative insufficiency results in the inability to sustain this focus or to change focus rapidly and efficiently from distance to near.
Accommodative insufficiency may result in symptoms of blurred distance, and/or, near vision, headaches, and eyestrain. Treatment for accommodative difficulties may include specially prescribed lenses, and in some, cases specialty visual therapy training.
Strabismus is a condition in which the eyes are not aligned in the same direction. In your case, one of your eyes turns in while your other eye is used for seeing. In some cases, the eyes may alternate turning in. This condition is called esotropia. If the eyes are not aligned, the brain must ignore or suppress the information from one eye or double vision will result. In most cases, strabismus is caused by the faulty control of the external eye muscles that move the eyes. It may be caused by more serious factors such as trauma, diabetes, or brain lesions.
Treatment of this condition may vary depending on age, severity and cause. Treatment may include glasses, prism lenses, eye muscle exercises (vision therapy) or surgery.
HYPEROPIA (hy-per-O-pee-a) or FARSIGHTEDNESS
The medical term for farsightedness is hyperopia. As with most refractive errors, farsightedness is commonly caused by the shape of the eye. Farsighted eyes are generally shorter from front to back or because the front curvature of the eye is flatter than normal. An uncorrected farsighted eye must use the near focusing system of the eye, normally only used for close-range tasks, to assist distance vision. As a result, this places an even greater focusing effort on close-range vision. Uncomfortable symptoms and fatigue are common for the uncorrected or under-corrected farsighted eye since the visual system is in a constant state of over effort.
Clarity and comfort of vision for the farsighted person depends on their degree of farsightedness and the efficiency of their focusing system. In general, farsighted eyes always see better at far distance than at closer distances. Farsighted adults gradually see less clearly at all distances due to a natural and expected decline in the eyes close-range focusing ability over time.
Farsightedness is most commonly corrected with eyeglasses or contact lenses. If adults require different prescriptions for distance and near, special dual-focus contact lenses are now available. Less commonly, refractive surgery techniques such as LASIK, or lens replacements are also treatment options for adults.
PRIMARY OPEN-ANGLE GLAUCOMA
Glaucoma is a condition where various factors cause damage to the optic nerve and resultant loss of vision. Many factors including family history, race, intraocular pressure, thin corneas, and/or, the appearance of the optic nerve can increase the risk of developing glaucoma. The ultimate diagnosis of glaucoma is based on these factors, as well as, analysis of the retinal nerve fiber layer and visual field studies.
Primary open angle glaucoma is the most common form of glaucoma. The exact cause of the disease is not completely understood but typically has some relation to the pressure inside the eye. Open-angle refers to the fact that the area where fluid drains from the eye is open or unrestricted. Primary open angle glaucoma is a slowly progressive disease that must be diagnosed and treated early to avoid irreversible loss of vision. Primary treatment involves the use of drops, but laser treatment, and even surgery, may be required in more advanced cases. Unfortunately, glaucoma has no symptoms until the disease is well advanced and significant loss of vision has occurred. For this reason, the health of the optic nerve must be closely followed to assure treatment is effective and vision loss is not progressing.
HOW TO ADJUST TO A PROGRESSIVE MULTIFOCAL
Your new progressive lenses provide you with the most natural vision possible. Modern progressive multifocal lenses have no visible lines and a smooth progression of power making them functionally and cosmetically the lens of choice for adult patients.
Utilizing your new progressive lenses is natural, but as with any new tool, it initially requires practice. For distance sight, simply, point your nose at your visual target. Just like a golf club, a progressive lens has a more efficient “sweet spot” in its center. Turning your head, rather than looking through the sides of the lenses will allow you to experience distance optimally. Viewing through the outer periphery of the lens may cause you to experience wavy, less efficient vision.
For middle-range tasks, such as computers, store shelves, or the dashboard of the car, simply lower your eyes slightly into the middle center of the lens. For reading, hold your material down, close to your body, and look through the lower portion of the lenses. For walking, look straight ahead. If you need to see the ground, simply lower your chin to view utilizing the upper portion of the lens.
It is rare to fully adjust to progressive lenses during the first week. Leaving it on as much as possible will hasten the process. As in everything else, adjustment varies per individual, however, with practice, and with patience, you will experience the many natural benefits of progressive multifocals.
DRY AGE-RELATED MACULAR DEGENERATION
Age related macular degeneration (AMD) is a deterioration of the central vision area of the retina called the macula. The macula is responsible for our fine central detailed vision. Although the exact cause of AMD is not known, it is thought to be an accelerated by the aging process. The risk of developing macular degeneration increases with age, family history, vascular status, active smokers, and lifetime sun exposure.
There are two forms of age related macular degeneration, a “wet” type, and a “dry” type. The “dry” type has a better prognosis. On average, this condition is slowly progressive and functional vision is maintained. Although there is no cure for dry macular degeneration, treatment is available. Nutritional supplements, protection from ultraviolet radiation, special medications, and laser treatment are all considerations depending on the degree of advancement of the condition. Careful monitoring is imperative to track possible advancement.
DIABETES & THE EYE
Diabetes is the second leading cause of blindness and may soon top the list of sight-loss conditions. Diabetes and its complications can affect many parts of the eye. Diabetic eyes are 25 times more likely to develop blindness than non-diabetic eyes. Diabetes can also cause earlier development of cataracts, a higher tendency toward glaucoma, dry eye symptoms, and, most importantly, damage to blood vessels nourishing the sensitive retina.
A comprehensive eye health examination may reveal early warning signs or simply the suggested presence of diabetes. Patient history, reported symptoms, observed changes in the retina, unexpected prescription changes, and early cataracts may all be an indication of diabetic complications. More frequent dilated eye examinations and the use of retinal photography is highly recommended for patients with the disease, patients that are suspects, and patients with a strong family history of diabetes
You have been diagnosed with an eye condition called amblyopia, sometimes referred to using a non-medical term as lazy eye. Amblyopia causes an eye and the brain to not working properly together. The most common causes of amblyopia are large differences in prescription need between the two eyes, strabismus (the eyes not pointing in the same direction), or an inability to see out of one eye from birth. To overcome this situation the brain generally suppresses or ignores much of the information from one of the eyes. Once this occurs the effected eye cannot achieve a normal level of vision despite an accurate prescription.
The successful treatment of amblyopia is highly dependent on the age of the patient. A young child has a better prognosis for recovering normal vision. Treatment generally includes eyeglasses, patching or occluding the normal eye to force the “lazy” amblyopic eye to work, and sometimes vision therapy. As a general rule, amblyopia treatment has little benefit after the visual system matures.
A cataract is a clouding of the eye’s natural lens, which lies behind the iris and the pupil.
Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world. In fact, there are more cases of cataracts worldwide than there are of glaucoma, macular degeneration and diabetic retinopathy combined, according to Prevent Blindness America (PBA).