In order to evaluate your child's vision, your child's healthcare provider will perform a history and physical, including a complete exam of the eyes. There are also many different types of vision tests that can be used to check your child's ability to see. Some of them can be used at any age, while some of them are used based on your child's age and understanding.
The following are some of the ways in which your infant's vision can be tested:
Response to light. An infant will blink in response to a bright light.
Pupil response. Measuring the response of the pupil (the black center part of the eye) by shining a penlight in the eye is one way to test an infant's vision.
Ability to follow a target. The most common vision acuity test in infants is a test to check their ability to look at and follow an object or toy.
Visually evoked response testing. These are tests that stimulate the eyes with either a bright light or special pattern. The infant is connected to a special monitor with attachments on the infant's head. The machine then records electrical activity in the brain as the lights and patterns are shown to infants.
Many of the above tests may be performed, in addition to the following:
Cover and uncover test. This test looks for movement and alignment of the eyes that may happen when a child is focusing on an object. One eye is covered with an opaque card while the child stares straight ahead. At this time, the examiner observes the uncovered eye.
Some of the same tests that are used for the toddler, in addition to the following, may be used, usually around age 3:
Visual acuity tests. Specific tests and charts may be used to measure both near and distant vision. In a preschooler, these charts may consist of pictures or stories instead of letters of the alphabet.
Color testing. This test helps determine color blindness in a child.
In this age group, formal vision tests can be completed with special charts or instruments that aid with testing vision. Both near and far vision can be evaluated.