Low Vision: Signs, Causes, & Treatments
When eye care professionals discuss the topic of low vision, they are generally not talking about standard prescription eyeglasses. Low vision aids refer to people with certain eye disorders, such as macular degeneration, other retinal eye diseases, malfunctions of the cornea, and congenital eye diseases. Congenital means present at birth.
For example, a baby can be born with a serious eye cancer called retinoblastoma or ROP. Sometimes, depending upon the cancer stage, the baby’s vision can be at least partially preserved.
However, some form of low vision aids for the affected eye may be required to maximize the child’s vision for the rest of their life.
Parents of newborns with ROP may notice a peculiar white spot in the baby’s pupil. This spot may be more pronounced in flash photographs, but ROP can also be seen with the naked eye.
Prompt treatment may save both the baby’s vision and life. Low vision aids will improve the quality of life.
Presbyopia
Low vision aids do not typically refer to the common age-related eye condition known as presbyopia. This condition affects nearly everyone without myopia, beginning at about the age of 40, and worsens slowly over time as the person ages.
Presbyopia is a normal part of aging for the eye and is not a disease. It’s caused by a thickening of the eye’s lens, which makes focusing on near objects more difficult because the lens is not as flexible as it once was.
Adding to the problem are age-related changes in the tiny muscles involved in seeing close objects clearly.
People with presbyopia but otherwise normal vision will still retain their distance vision, as only close-up vision is affected. Although unlikely, those with myopia can still develop presbyopia.
What Is Myopia?
Myopia is another term for nearsightedness and is caused by a focusing defect related to an abnormal eyeball curvature. This faulty curvature causes light to misfocus on the retina at the back of the eye. Instead of landing precisely on the retina, light lands in front of it. This results in a fuzzy or blurry image instead of a clear one when looking at a distant object.
Myopia does not affect close-up vision.
Myopia may be mild or severe. Correction for myopia is always referred to in negative numbers on a prescription for eyeglasses or contact lenses.
Many people with myopia retain their ability to see tiny prints and small objects close-up well into advanced age. They are considered “near-sighted” and may not be affected by presbyopia at all.
Presbyopia is easily treated with glasses that magnify print and other small, close-up objects. These may be purchased without a prescription for persons with otherwise normal vision.
These glasses will be labeled with numbers indicating their magnifying power. Always beginning with a plus sign, for example, +1.50, these lenses may be all a person with presbyopia needs to read and do other close-up activities.
Typically ranging in power from +0.75 to +3.00, these eyeglasses may provide an effective and inexpensive solution for many with presbyopia not involving myopia or hyperopia (far-sightedness).
These eyeglasses are available in both standard and designer frames. If you prefer the look of a designer frame and don’t mind paying for it, that’s fine, but these expensive frames don’t necessarily hold quality lenses. Always ask your eye care professional for advice before purchasing any over-the-counter eyewear or product.
For those with myopia, simply wearing a pair of magnifying glasses will not work, as they won’t be able to correct myopia at normal reading distances. These people will need to either wear magnifying glasses over their regular ones (there are clip-on versions available), use prescription bifocal lenses, or use special lenses called progressives.
Progressive Lenses
Progressive lenses are a major improvement over bifocals. Instead of a confusing and unattractive line of demarcation at the bottom of the lens, progressives allow the individual to see at varying distances by simply learning to “point” the eye and head.
The lenses have no visible lines of demarcation and are much easier to adjust. They consist of lenses with blended areas of focus. The distance part of the lens will be at the top; the up-close part will be towards the bottom. In between are several focusing points, none of which are visible.
Bifocals can cause headaches, dizziness, and nausea and are very hard to use for many people. Some simply cannot tolerate them at all. Before progressive lenses became available, people unable to adjust to bifocals had to have two sets of glasses, always switching back and forth.
An old wives’ tale states that wearing glasses will weaken the eyes, which is untrue. In fact, not wearing glasses when needed will contribute to eyestrain, pain, dizziness, and headaches.
What Is Low Vision?
Low vision is defined as having visual problems with seeing clear images, recognizing faces, differentiating colors and shapes, and other visual impairments involving daily activities like reading, doing certain hobbies, and driving.
Low vision is further defined as being both incurable and not amenable to standard available treatments. It also involves a marked degree of visual impairment. For example, persons with age-related macular degeneration or ARMD may have so much retinal damage that their visual field is limited to that of an image with a hole punched out of the middle.
Everything in that hole is absent, making ordinary activities like doing puzzles, writing, reading, and recognizing faces all but impossible. ARMD is a cruel, unrelenting disease, treatable in some cases but not curable.
Reduce your risk by protecting your eyes from sun damage and not smoking. Ask your eye care professional about special vitamin formulas designed to reduce the risk of ARMD.
Brain injuries may also cause low vision problems. These injuries may result from accidents, strokes, tumors, or other brain conditions.
Low vision may also be associated with other inflammatory, autoimmune diseases like multiple sclerosis and rheumatoid arthritis. Many people think rheumatoid arthritis is only a disease of the joints, which is untrue. Both rheumatoid and psoriatic arthritis may cause significant visual impairment by setting off a worsening, chronic inflammatory state, damaging delicate eye structures.
Magnification Devices for Low Vision
Opto-Electronic Systems: Augmented Reality Glasses
Augmented reality glasses for low vision belong to the opto-electronic group of devices. These devices use a screen to project an image rather than require the patient to hold a magnifier. Virtual reality glasses work by using a small camera to capture images the person is looking at.
These images are then projected directly onto the retina of the right eye. From there, the patient can adjust the images as needed, allowing them to zoom in, change light/dark contrast, and enlarge the image.
Essilor Augmented Reality glasses have the important added advantage of being as light and easy to use as a pair of regular corrective eyeglasses.
Handheld Magnifiers
These are small, usually round or square, magnifying glasses mounted on a handheld plastic or metal frame. They are light, portable, and easy to carry and use anywhere. Opto-electronic systems for low vision are typically large, heavy, and limited to use in the home.
Loupe Magnifiers
These are very small magnifiers mounted on another pair of eyeglasses to provide very high magnification powers. These are used to help people with very limited vision to see better. In the medical field, they’re also used to allow surgeons to perform delicate procedures requiring much more visual power than the unaided eye or standard magnifier can provide.
Ophthalmologists and optometrists may also use small, hand-held, round loupe magnifiers to examine the back of the eye. These loupes are held between the fingers and aimed into the dilated eye. Through the loupe, the eye doctor can see and examine the retina and optic nerve in great detail, spotting tiny trouble spots and evidence of eye disease while it’s still in its early stages.
These loupes are especially useful in evaluating and treating diabetic eye disease, allowing the eye doctor to see serious changes in the eye’s blood vessels caused by uncontrolled or poorly controlled diabetes.
Jewelers also use loupe magnifiers to examine gems for authenticity and quality. These loupes may be hand-held or attached to some form of headgear that leaves the hands free. Not as powerful as medical loupes, jewelers’ loupes are less expensive. However, they still allow the jeweler to evaluate the crystal structure and quality of a diamond or other gem.
Find a Top Eye Doctor Near You
If you’re concerned about low vision for yourself or a loved one, you will be interested to know that some eye care professionals specialize in low vision devices and treatment. Our comprehensive list of top-rated eye doctors may include low vision specialists near you.
Our doctors also provide general eye care services, such as annual eye exams, dilated eye exams to check the health of the retina and optic nerve, prescriptions for eyeglasses and contacts, and treatment of various eye conditions.
It’s always best to consult an eye care professional before using any type of magnification device. Only an eye doctor can recommend the best type of low vision aid for your needs.
Protect your eyesight by ensuring you see an eye care professional at least once a year.
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