What visual test is NOT typically performed in children under preschool age?

• A. Fixation
• B. Tracking
• C. Reading a Snellen chart
• D. Pupillary reflex

Answer: (C)

Reading a Snellen chart is not typically performed in children under preschool age primarily because this test requires the ability to recognize letters and numbers, which most children in this age group have not yet learned to do. The Snellen chart assesses visual acuity by asking the individual to read letters of progressively smaller size, and preschool-aged children usually do not have the cognitive or visual processing skills fully developed to perform this task accurately.

In contrast, the other visual tests mentioned—fixation, tracking, and pupillary reflex—are appropriate for younger children. Fixation assesses whether a child can focus on an object, tracking evaluates the ability to follow moving objects with their eyes, and testing the pupillary reflex involves observing the pupils' reaction to light, which is a straightforward assessment that can be done at any age. These tests provide useful information about the child’s visual system even before they reach an age where they can read or identify letters.