Types of visual screening tests
In order to evaluate your child's vision, your child's physician will perform
a history and physical, including a complete examination 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 types of
visual screening tests:
Visual screening tests for an infant:
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) to 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.
Visual screening tests for an older infant and
toddler:
Many of the above tests may be performed, in addition to the
following:
- Cover/uncover test - This test looks for movement and alignment of the eyes
that may occur when a child is focusing on an object. One eye is covered with
an opaque card while the child stares straight ahead, at which time the
examiner observes the uncovered eye.
Visual screening tests for a preschooler:
Some of the same tests that are used for the toddler, in
addition to the following, may be used, usually around the age of 3:
- Visual acuity tests - Specific tests and charts may be used to measure both
near and distant vision. In the 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.
Visual screening tests for a school-aged children and
adults:
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.