Get the FAQ’s About Your Eyes
Answers to questions about vision problems
What is nearsightedness?
If the eyes can see close-up objects clearly but distance ones are blurred, they are said to be nearsighted (Myopia). Often, the onset of nearsightedness is so gradual that the blurring is not noticed until one realizes they cannot see as well at those around them. Forty percent of the total U.S. population will develop nearsightedness. Usually, if nearsightedness occurs, it begins before the age of 25.
The cause is not known for certain. Some theories say it is caused by visual stress. For example, during school years, the eyes are subjected to a lot of reading and close work. Others blame metabolism, diet, lighting conditions, posture while reading or heredity. Squinting is a common sign of nearsightedness. In children, sitting too close to the television set, poor school grades and lack of interest are other indications. A person may become aware of a lack of detail on distant objects, such as road signs or scoreboards in ball parks. The care of nearsightedness uses glasses or contact lenses. At present, there is no certain prevention for nearsightedness.
What is farsightedness?
Farsightedness (Hyperopia) is a kind of vision in which seeing is better adapted for far than near. The farsighted person constantly maintains a focusing effort to keep clear vision when looking at a distance and an even greater focusing effort is needed for clear vision when reading. This greater effort may cause fatigue and results in poor efficiency when doing concentrated work. If a person’s focusing ability is good, or the amount of farsightedness is low, they may be able to focus enough to maintain clear vision at distance, even 20/20 vision.
Reading glasses are prescribed to make near tasks more comfortable and efficient. If the person’s focusing ability is not good, or the degree of farsightedness is high, they cannot focus sufficiently, even for far distances. In this case, lenses would be necessary all of the time. Possible symptoms for farsightedness include difficulty in concentrating and maintaining clear vision when reading, eye fatigue after close work, burning eyes and poor reading ability. It is difficult to discover farsightedness in many screening exams. The care of farsightedness also uses glasses or contact lenses.
What is astigmatism?
Astigmatism is primarily caused by an irregular shape of the eye. If your eyes were “perfect”, they would be spherical, similar to the shape of a ping-pong ball. Few eyes have this perfect shape, but instead are more egg-shaped. This shape causes astigmatism and results in a distorted and blurred focus rather than a sharp, clear focus. Small degrees of astigmatism may cause very little distortion, but can be the cause of headaches or fatigue. Astigmatism can be easily detected during an eye exam and comfortably corrected with glasses or contact lenses. It usually exists in combination with nearsightedness or farsightedness. Astigmatism is not a disease.
What is 20/20 vision?
Visual acuity is a measurement of how well you are seeing. Standard vision is 20/20, and it might be easier to answer this question by answering the question “What is 20/60 vision?. As a point of reference, a person who’s vision is 20/60 would need to be 20 feet away from a sign to see it as clearly as another person with good vision would see it from 60 feet. Less than 20/20 vision can result from vision conditions such as nearsightedness, farsightedness, astigmatism or certain eye diseases. In most cases, eye glasses, contact lenses can improve a person’s vision. It is important to understand that 20/20 is only standard vision. Some people can see better than this standard, and some people see less than this standard.
What is Glaucoma?
Glaucoma is an eye condition in which the normal fluid pressure inside the eyes slowly rises, causing damage to the optic nerve. Glaucoma is a leading cause of blindness in the United States and is the number one cause of blindness in Blacks. Constantly, a clear fluid is pumped into the eye. In glaucoma, this fluid drains too slowly out of the eye. As the fluid builds up, the pressure inside the eye slowly rises. Unless this pressure is controlled, it may cause damage to the optic nerve and loss of vision results. Glaucoma is a slow onset condition. Damage to the optic nerve can start a long time previous to the patient noticing any loss of vision. Nearly 3 million people have glaucoma. Although anyone can get glaucoma, some people are at a higher risk. They include anyone over the age of 60, Blacks over the age of 40, people with a family history of glaucoma and people with higher than normal eye pressure.
What are cataracts?
Inside of our eyes is a lens that helps us when we focus. This lens is normally clear so that light can easily pass through it. When this lens loses its clearness, the patient is diagnosed with a cataract. Cataracts interfere with vision by blocking light entering the eye.
There are many things that can cause cataracts. Age-related cataracts are very common. Being hit in the eye can cause a cataract. Cataracts can result as a side effect from certain medications. Infra-red light definitely causes cataracts, and it is thought that UV light can also bring them.
Once cataracts are detected, adequate vision can be maintained with the help of prescription lenses. Changes in prescription can occur more frequently when a cataract is present. Generally, surgery is recommended when vision cannot be corrected with glasses, and normal activity is affected. Typically, cataract surgery is a simple procedure, and because of the dramatic improvement in vision, most people are glad they decided to have their cataracts removed.
Why do I need bifocals?
There is a lens in your eye that, for the first 40 years of your life, is able to change shape to help a person focus up close. As the years go by, this lens begins to harden, and focusing becomes more difficult. Many people say their “arms aren’t long enough”. The person ends up with two completely different prescriptions, one for clear distance vision, and one for clear near vision. Bifocals or reading glasses helps to solve this problem.