Certified Ophthalmic Technician (COT) Test 2025 – 400 Free Practice Questions to Pass the Exam

When a child sees only two red lights through a red lens placed over one eye, this typically suggests that the child is suppressing the vision in the other eye. The child should normally see three red lights: one from the eye with the lens and one from each eye. However, if only two red lights are perceived, it indicates that the brain is ignoring or suppressing the input from the left eye, likely due to a misalignment or other issue with binocular vision.

In this case, the suppression mechanism often occurs as a way to prevent double vision that could arise from strabismus or another issue, where the eyes do not properly align or cooperate in their movement. Hence, the child is not utilizing the visual input from the left eye, leading to the observation of only two lights.