You may have heard that reading a lot causes near-sightedness, but is there any truth to this rumor?
The exact causes of near-sightedness, or myopia, have been debated by scientists for a long time. Some are convinced that the condition is hereditary, while others point to environmental factors as the culprit.
On the one hand, some researchers insist that this condition is all in the genes, and that you have mom and dad to thank for those glasses. A study conducted by scientists in the United Kingdom measured the eyeball size of 400 sets of twins. Using mathematical modeling techniques, they found that 89% of refractive vision problems like myopia can be attributed to genetic factors.
On the other hand, there's also evidence that rates of literacy and myopia are linked, so that when more people in a given population are able to read, the number that become nearsighted also goes up. One famous study of the Eskimos in Alaska found that myopia increased considerably when their children began attending school and doing a lot more reading.
The question remains, should you cut down on reading to save your eye sight?
The answer is simply, no. While close-up work like reading seems to play some role in the development of myopia, the most significant factor continues to be heredity. If your parents are nearsighted, you probably will be, too.