Red reflex

The red reflex refers to the reddish-orange reflection from the eye's retina that is observed when using an ophthalmoscope or retinoscope.

Many eye problems may be detected by this test:
 * cataracts - show Leukocoria, or white coloration of the eye
 * retinoblastoma - shows leukocoria.

Newborns are regularly screened for retinoblastomas with an ophthalmoscope.

According to Bates Guide to Physical Exams, retinal detachment and vitreous would cause the patient to not have a red reflex.