BehindTheMedspeak: Can reading in the dark damage your eyes?

Will each of the seven people alive today who grew up without hearing this over and over again please raise their hands?

Thank you.

Anahad O'Connor, in his "Really?" feature in the July 4 New York Times Science section, addressed the headlined question.

Here's what he wrote.

The Claim: Reading in the Dark Will Damage Your Eyes

The Facts: Everyone who has ever held a flashlight to a book at night has probably heard the dire warnings about reading in the dark. It will weaken your eyes. It can ruin your vision.

But according to most ophthalmologists, while reading in the dark might strain your eyes and give you a headache, the notion that it can cause lasting damage is wrong. Most people can expect to experience some decline in their vision as they age, and genetic research shows that it is family history above all else that determines to what extent your vision will weaken.

But some researchers argue that putting too much strain on your eyes as a child or young adult, like the kind caused by reading in the dark, or simply reading for prolonged periods in general, might contribute to the decline of your eyesight later in life.

Population studies in the United States and other countries have shown, for example, that the rates and severity of myopia are always greatest among people who attain the highest levels of education, as well as those whose occupations require them to do a great deal of reading, like lawyers, editors and doctors.

But most of those studies have not taken into account economic factors like limited access to eye doctors.

One ophthalmologist who has studied the claim, Dr. Robert Cykiert at New York University Medical Center, is adamant that the strain reading puts on your eyes — in poor light or not — is safe. "It may create fatigue," he said, "but it cannot hurt your eyes in any way."

The Bottom Line: Most experts say reading in the dark is safe, despite circumstantial evidence that constantly straining your eyes can weaken your vision.

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I think it's equally likely that constantly straining your eyes and all their intrinsic structures will strengthen your vision.

Parents, you might want to forbid your children from reading this post — whether in broad daylight or other, less luminous circumstances — since not doing so will definitely undermine your arguments.

FunFact: The retina of a 60-year-old receives 25% of the light absorbed by a 10-year-old child in the same environment, a result of gradually increasing opacification of the eye's lens with aging.

Much of the disagreement and push-pull about reading in dim light may be explained by that simple fact.

The way a kid looks at things, there's much more light than the parent sees.

The parent says it's too dark and the child replies, "It's so bright I gotta wear shades."

More here.