An eye exam is a part of each well visit. However, according to the recommendations of the American Academy of Pediatrics, children should have their vision screened at age 3 years.
To have their vision checked, children must know basic shapes, such as a star, moon, cup, etc., or know the alphabet. If your child doesn't know shapes or letters, and you have concerns about his/her vision, your child's primary care provider might refer you to see a pediatric ophthalmologist.
For children without risks, the American Optometric Association recommends an exam at 6 months, at 3 years, and then every 2 years for 6-18 year olds.
For children at risk, it's recommended to follow the advice of your pediatrician. Risks include a mother's infection during pregnancy, difficult labor, premature birth, low birth weight, a family history of eye disease.