Nearsightedness is the only refractive condition that increases significantly in prevalence throughout the school years. It significantly affects about three percent of five- to nine-year-olds; eight percent of those age 10 to 12; and about 16 percent of teenagers.
The cause of nearsightedness is not known for certain. More than one factor may be involved, but the two major theories indicate that nearsightedness is often inherited or caused by visual stress.
One optometric study of 200 families in one community found that 45 percent of the nearsighted children had parents who were both nearsighted, and 40 percent had one nearsighted parent. There also appeared to be a stronger link between nearsighted mothers and daughters than myopic fathers and sons. Generally, the children had higher degrees of nearsightedness than their parents.
The fact that the prevalence of nearsightedness increases with age lends weight to the theory that nearsightedness is caused by the undue stress children place on their vision. Human eyes were intended for sharp, clear seeing at a distance. They were not designed to focus on books or other close work for hours, to read computers, to peer through microscopes, or to do any of the near vision tasks required of them today.
Prescription lenses can improve visual acuity, but periodic lens changes are usually needed because nearsightedness is a progressive vision problem. Today, however, optometrists use lenses and sometimes contact lenses to try to prevent, slow, or stop the progression of nearsightedness. The condition itself tends to stabilize about age 25.
Early warning signs of nearsightedness include:
- Complaints of a momentary blur when looking from a book to a distant object, such as a chalkboard
- Less clear distance vision at night
- Squinting when looking at distant objects
- Constant sitting close to the television set
Recommendations for Parents of Nearsighted School Children
- Provide the child with good, glare-free lighting for reading, doing other close work and watching television.
- When the child reads, encourage him or her to maintain good posture, hold the book 12 to 16 inches from the eyes, keep both the left and the right pages at an equal distance from the eyes and tilt the book up.
- Encourage the child to take occasional breaks during prolonged reading to look up at distant objects for a few seconds and to rotate the eyes in a wide circular pattern for about 30 seconds.
- Avoid the use of reading materials with very small print or poor quality print.
- When watching television, the child should sit at a distance of at least five times the width of the screen. The overall light in the room should be soft.
- If children like to read while riding in the car, have them take frequent eye breaks by looking out the window.
- When playing video games or working on a computer, reduce room lighting somewhat, be certain lamps do not reflect on the screen and use shades or drapes to reduce glare from windows. Adjust the screen brightness to three or four times the brightness of the room lighting. Encourage the child to take breaks at least every hour.
Source: American Optometric Association. |