Farsightedness is actually normal in young children and not a problem as long as it is mild. If a child is too farsighted, vision is blurry or the eyes cross when looking closely at things. This is usually apparent around the age of two. With farsightedness a person has to focus their eyes to see far away and focus them even more to see up close. As long as a person is able to do the amount of focusing needed, he does not need glasses. However, if the person is unable to focus as much as they need to or if the person's eyes cross when focusing, then glasses are required.

Almost everyone has some amount of astigmatism (oval instead of round cornea). Eyeglasses are required only if the astigmatism is strong.

Unlike adults, children who need glasses may develop a second problem, called amblyopia (or the inability to see 20/20 even with glasses on). Amblyopia means even with the right prescription, one eye (or sometimes both eyes) does not see normally. Amblyopia is more likely to occur if the prescription needed to correct one eye is stronger than the other or if the prescription in both eyes is very strong. Amblyopia can also occur if one eye is crossing or drifting. Wearing eyeglasses can prevent amblyopia from developing or may treat amblyopia if already present.