Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure below shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it.
Mark found that that he was having trouble seeing things at a distance when driving and had to sit closer to his monitor at work in order to see clearly.
Are images being focused in front of or behind Mark's retina?