At the recent ARVO meeting in Seattle, a number of vision scientists described studies in which significant vision loss could not be detected by standard visual acuity, but could be detected by contrast sensitivity and glare testing.
Dr. Pinakin Davey of Western University School of Health Sciences, was interviewed about his findings by MDTV. He described studies of patients with a rare genetic condition that typically presents with abnormalities in the front of the eye on the cornea. None of the studies using the standard high contrast E Chart detected any vision loss. He thought these results were contradictory since malformations of the cornea should lead to detectable vision changes. He therefore conducted another study where he evaluated both contrast sensitivity and glare. His results showed a significant, previously unreported, visual function deficit and confirmed his theory that any malformations in the cornea should lead to some type of detectable vision loss when the proper measurement technology is used.
Check out the video below for a video description of his studies and results.