The double vision and halo effect are common in the visual field test. Your eyes are looking ahead but you are trying to see your periphrial vision. This causes your eyes to cross sightly and the conflicting messages from the two different optic nerves in your brain are interpreeted as a double vision and blurrines (halo).
The double vision may be simply from eye strain. It is the halo effect you would need
to worry about. This could indicate cataracts. When you take a visual field test, you stare
at a dot in the center of the screen. If you cannot see many of the blinking lights or
you do see a halo, see an specialist.
Double vision and halo effect are abnormalities of sight. They are associated with neurological disorders, but also occur due to muscular disorders, cancer, eye injury, brain injury, cataracts and diabetes.
