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Eye Health FAQ

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1. What is nearsightedness (myopia)?

Simply put, nearsightedness is the result of the eye being too long from front to back and/or the optical power of the eye is too strong. This condition (also called myopia, [my-ohp-ee-ah]) causes blur when viewing objects at a far distance. Children are often farsighteded at birth and then they develop nearsightedness as the eye grows longer. It is not uncommon for children to go from 20/20 vision to 20/200 vision over a period of months during times of rapid growth.

Signs and Symptoms of nearsightedness:
As nearsightedness develops, a child’s pupils may seem unusually large, and you may notice the child “squinting” a lot when they try to see things such as the numbers on a calendar at a distance of 15 to 20 feet. Some children tend to read a lot more as nearsightedness develops because print remains clear even though object a few feet or more away are blurred. Some scientists think that excessive reading may contribute to nearsightedness, but this may or may not be the case. More recent studies are focusing on peripheral retinal defocus as the cue for myopia progression.

2. What is farsightedness (hyperopia)?

An eye is said to be farsighted if it is too short from front to back and/or if the optical power of the eye is too weak. This condition (also called hyperopia, [high-per-ohp-ee-ah]) causes the muscle that focuses the eye to contract excessively when viewing at any distance. Smaller amounts of farsightedness can cause the eyes to tire rapidly for reading or other close work. Sometimes larger amounts of farsightedness can cause one eye to turn inward either intermittantly or constantly.

3. What is astigmatism?

Astigmatism is condition in which the eye cannot form a sharp focus at any distance. It is usually caused by a failure of the cornea to have a uniform curvature in all directions. The cornea is the window of the eye and is located just in front of the iris and pupil.

The end of an egg has the same curvature up and down, cross-wise, and diagonally. A cornea without astigmatism also has the same curvature up and down, cross-wise, and diagonally. When you look at the side of an egg lying on a table, it has a weak curvature in the crosswise direction, or horizontal direction, and a much stronger curvature in the up-and-down direction. A cornea that has astigmatism has a steeper curvature (usually in the up-and-down direction) and a flatter curvature in the crosswise or horizontal direction.

Signs and Symptoms of astigmatism:
Astigmatism prevents the eye from forming a sharp focus, so astigmatism is usually associated with some blur at both distance and near. Headaches , eye discomfort, and a tendency to avoid reading and other prolonged close work are also often associated with astigmatism.

4. Is there anything that can be done about colorblindness?

Yes, and no. There are various kinds and severities of color blindness. A total inability to see color is rare. Perhaps 7% of males USA have either a decreased sensitivity to red, or difficulty distinguishing between red and green. Although color blindness or color vision deficiency cannot be corrected, spectacle lenses and/or contact lenses can be used to allow those who have these problems to do a better job of sorting out or identifying colors. It is important that children be tested for color vision problems at an early age, since it can affect both their school performance and their career choices.

5. Although my vision is excellent for far away seeing, why am I having trouble with reading?

Near vision requires the ability to refocus the eyes and converge them so that they maintain a correct “aim” at the print. Because the eyes move in jumps called saccades as they move across a line of print, eye coordination is also important for easy reading.

If maintaining a clear view of print one eye or the other separately is the problem, the most likely causes are either farsightedness or astigmatism, or a combination of both if you are under 40 to 45 years of age.

The most common cause for near blur in adults over 40 is presbyopia. Presbyopia is a result of a normal change in the lens of the eye (located just behind the pupil). Adults entering presbyopia often find they need more light to see up close, and they often have to hold reading material at arms length.

Trouble with reading can also be a problem with controlling the 12 muscles that aim the eyes. There are also health related problems that can interfere with reading and other near vision tasks. A complete vision exam by an optometrist can reveal the basis of reading problems and also determine the options for restoring you to clear and comfortable reading.

6. My child passed the vision test at school, so is there any reason why he should be seen by an eye doctor?

Some doctors call the inside of the eye “the most important square inch of the body.” When your optometrist does an examination, he examines the inside of the eyes for many conditions related to general health as well as eye health. School vision tests will usually detect blurred distance vision although a clever child can sometimes even pass a “read the chart” test with seriously impaired vision. Some school screenings also screen for other problems such as focusing and convergence difficulties, eye muscle imbalance, pupillary function, and visual field loss. Even the most thorough school screening cannot substitute for a complete eye examination by a doctor. 90% of learning is based on vision. All children should have regular professional eyecare.

7. Can behavior problems in school be related to vision problems?

Most learning is based on vision. Children who cannot see clearly at chalkboard distance and/or near reading distance become frustrated with learning and this can lead to boredom and problems with behavior. The same is true if their ability to accurately aim and easily refocus from one distance to another is impaired. Sometimes a child who is well-behaved in the lower grades, becomes a behavior problem when the reach the 9 to 12 year-old range. This can be due to eye changes that commonly occur with growth spurts. A child with a small amount of farsightedness in grades 1-3, may become rapidly nearsighted due to an elongation of the eyes related to a sudden growth spurt in the fourth, fifth, or higher grades.

8. “Floaters” – What are they?

Floaters are dots or chains of dots or shadows that drift across our field of vision. Almost everyone has floaters that appear from time to time. They are shadows cast upon the retina of cellular debris within the eye. Floaters are annoying but not harmful. If you experience sudden-onset floaters, which are usually seen as a cloud of many, many floaters that appear rather suddenly, you could be experiencing a symptom of retinal detachment. This type of floaters may be accompanied by flashes of light that seem to appear and then be gone, only to return – usually in the same direction that you had seen them earlier. Sudden onset floaters, and/or flashes of light could be a sign of retinal detachment or retinal separation. If you experience these symptoms, you should be checked for retinal detachment within 24 hours.

9. What is a cataract?

Light rays are focused by the cornea and crystalline lens onto the retina. If the crystalline lens loses its clarity, the flow of light into the eye is disrupted. When a fast flowing river encounters large boulders that disrupt the flow of water, the term cataract is used. When the lens of the eye develops a loss of clarity that disrupts the flow of light, the term cataract is also used for that condition.

Cataracts can swell and cause a secondary glaucoma and permanent, irreversible damage to the optic nerve. When the advance of a cataract causes your lens-corrected vision to interfere with your normal life, or if the cataract reaches a point at which secondary damage is imminent, an ophthalmic surgeon can remove the lens of the affected eye and replace it with an artificial lens. These artificial lenses are called implants, and they are highly successful in restoring useful vision. When your optometrist diagnoses a cataract form, he will tell you about it and either refer you to an ophthalmic surgeon or recommend re-evaluation at a later time so that the growth of the cataract can be measured and monitored.