"If a tear film is a little on the dry side from not blinking sufficiently…then the quality of vision suffers," said Rosen. "It's sort of a temporary phenomenon."
Some of the strain can be avoided, Chang said. If you are looking at something up close, it's a good idea to take breaks and look into the distance.
"I don't think people were meant to be looking at a computer screen all day long," he said, but "it's not going to cause long-term damage."
He said children may sit close to the screen because they can. "You have more of a range of accommodation and you can sustain it for long periods of time."
Of course, it may also signal a problem.
"If a kid is doing that, it may be that they need a pair of glasses," said Chang.
Answer: Sometimes Many eye problems are genetic, but as with all genetic problems, inheritance is not guaranteed.
"There's a higher risk, but it doesn't mean you're going to suffer," said Pepose.
"The important thing is that some eye conditions can definitely be passed down," said Chang.
"Things like glaucoma are definitely inheritable," he said. "That really reinforces the fact that it's generally good to get a general eye exam."
Chang said some problems are gray areas -- combinations of inheritance and environment -- such as refractive errors.
Studies show that problems such as nearsightedness and farsightedness seem to have some relation to whether a parent had the problem.
Of course, some vision problems have nothing to do with genetics.
"Cataracts is an age-related degeneration of the lens -- that's something that happens to everybody," said Chang.
Some age problems are inevitable.
"Cataracts are not a disease," said optometrist Harvey Moscot of Moscot Eyewear and Eyecare in New York City. "It's a normal aging change, not unlike gray hair. If everyone lived long enough, they would get cataracts."
But at the same time, cataracts, like many vision problems, can be fixed.
Cataracts, a clouding of the lens caused by the folding of proteins, can be removed to fix the problem.
"There's a lot of research now on preventing cataracts," said Moscot. But for other ailments, preventatives are known.
Many of the eye ailments that affect people when they age can be eased by following general health advice. A balanced diet can play a role in preventing some problems, as can giving up smoking. Rosen added that controlling cholesterol and sugar levels could help as well.
Of course, not all problems can be fixed completely. Moscot said that for many eye ailments, he tells his patients that their options are limited to LASIK laser eye surgery and glasses.
Answer: Myth -- mostly
Diet is important to good vision, but that doesn't mean that eating carrots all day will give you eagle eyes.
Vitamin A deficiency may lead to poor vision, but having an excess of the vitamin does not enhance vision further.
"In America it's not an issue, because our diets have plenty of vitamin A," said Moscot.
Some foods can help eyes, however.
Dark green vegetables, such as spinach and broccoli, for example, contain lutein, which is found as a yellow spot in the retina, called the macula.