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- Varilux lenses
- Popular brand of progressive addition contact lenses (sometimes called multifocal lenses).
Allows the wearer to focus through different prescriptions at different distances through the same lens.
See Free Eye Tests.
- vitrectomy
- Removal of the gel from the center of the eyeball, because blood and scar tissue in the gel block sight. An eye surgeon replaces the clouded gel with a clear fluid.
- visual acuity
- Measure of eye’s ability to distinguish object details and shape. Assessed by smallest
identifiable object that can be seen at a specified distance, usually 20 feet for distance
vision and 16 inches for near vision.
See Free Eye Tests.
- visual angle
- The angle formed by two rays of light or two straight lines drawn from the extreme points of a viewed object to the nodal point of the eye Roughly speaking, the width of your thumb at arm's length is approximately 2 degrees.
- visual field
- Extent of space visible to an eye as it looks (fixates) straight ahead. Measured in degrees
away from fixation.
See Free Eye Tests.
- visual field test
See Free Eye Tests.
- vision correction
- Any of a variety of appliances or surgical techniques used to correct less-than-perfect
vision. Includes eyeglasses, contact lenses and refractive vision correction techniques such
as Laser In-Situ Keratomileusis (LASIK), Photorefractive Keratectomy (PRK),
intrastromal corneal rings and clear lens extraction.
See Laser In-Situ Keratomileusis, Photorefractive Keratectomy, Prescription Eyeglasses, Refractive Surgery in Eye Care Encyclopedia.
See Free Eye Tests.
- vision tests
- Any test which assist in measuring the visual acuity of the eye.
See Visual Acuity in Eye Care Encyclopedia.
See Free Eye Tests.
- Visx laser
- One of two primary manufacturers of the Excimer laser used in refractive eye surgery.
See Free Eye Tests.
- vitamins
- Essential organic compounds required in trace amounts for normal growth and metabolism
in the body. Scientists are just beginning to understand the important roles of vitamins in
the health of eyes. Significant evidence suggests that some vitamins are critical to the
maintenance of healthy eyes. For instance, Vitamin A is proven to help prevent night
blindness; Vitamin C helps increase visual acuity and reduces the risk of developing
glaucoma; and vitamin E may help prevent cataracts. In addition, minerals like Copper,
Selenium, Manganese and Zinc all seem to play a part in maintaining eyes. Several
commercial vitamin products are now available specifically for the eyes.
See Free Eye Tests.
- Vitreous
- A clear, jelly-like liquid that fills the middle of the eye. Also called the vitreous humor.
See Free Eye Tests.
- vitreous detachment
- Separation of vitreous, which is the jelly-like substance that fills the eye behind the lens,
from the retinal surface. Frequently occurs with aging, but may occur in diseases such as
diabetes and severe myopia. Usually harmless, but can create retinal tears, which may in
turn lead to retinal detachment.
- Von Hippel’s angioma
- Also known as Von Hippel-Lindau disease, this hereditary disorder is characterized by
tumors of the retina, central nervous system, and visceral organs. In the eye, the disease
shows up as blood-filled retinal tumors that may lead to blood leakage and retinal
detachment.
See Free Eye Tests.
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