Different tests can be used to help diagnose a squint and assess the level of vision. These will vary according to your age, but may include sight tests like:
Looking at a light
Matching letters and pictures
Reading a letter chart
Looking at visual targets at different distances, first with one eye covered and then the other
Other tests may also be needed to determine whether glasses are needed. Retina and optic nerve examination to make sure there are no other problems. In most cases, eye drops will be used to widen the pupils before the eyes are examined. This will make it easier for the ophthalmologist to study the back of the eyes and measure the eye power correctly.
Other tests for squint involve measuring depth perception, evaluating double vision and synoptophore evaluation.