Babies should be able to see as well as adults in terms of focusing ability, colour vision and depth perception by 6 months of age.
Some parents are surprised to learn that preschool-age children do not need to know their letters in order to undergo certain eye tests, even when they are too young or too shy to verbalize.
Your eye doctor will want to rule out amblyopia, or "lazy eye," which is decreased vision in one or both eyes without detectable anatomic damage. Unfortunately, amblyopia is not always correctable with eyeglasses or contact lenses and may require eye patching to strengthen the weaker eye.
Crossed or misaligned eyes (strabismus) can have different causes, such as problems with muscle control in the affected eye or eyes. Strabismus is a common cause of amblyopia and should be treated early in childhood so vision and eye teaming skills can develop normally.
This is the inability to maintain eye alignment when viewing near objects. Convergence insufficiency can cause eye discomfort and even double vision when reading.
Your eye doctor also may test your child's focusing ability (accommodation), depth perception, colour vision and more.
Your eye doctor will closely examine your child's eyelids to look for abnormal or infected eyelash follicles, bumps, eye discharge and swelling (edema). The doctor also will examine the cornea, iris, and lens to look for cloudiness (opacities) or other irregularities.
Remember that appropriate vision testing at an early age is vital to insure your child has the visual skills he or she needs to perform well in school.
A child who is unable to see print or view a blackboard can become easily frustrated, leading to poor academic performance.
Some vision problems, such as lazy eye, are best treated if they are detected and corrected as early as possible while the child's vision system is still developing.