Help and frequently asked questions

Why does the optician cover one of my eyes?

Answer: 

This part of the eye test is called the divergence/convergence test. The alignment of eyes are observed. The eyes are alternately covered and uncovered while the person looks at  a target. This tests the resting position of the eyes and their response to focusing and targeting the object. Misalignment may indicate a squint, an uncorrected optical error, or a neurological problem.