Local Doctor Invents Revolutionary Prism Glasses
Massachusetts Eye and Ear Infirmary is paving the way for glasses technology to treat hemianopia.
More than one million Americans have lost the ability to see in one half of one or both of their eyes due to trauma, strokes, or tumors. This condition, called hemianopia, causes patients to trip over objects outside of their range of vision, and bump into walls and people. Dr. Eli Peli of the Massachusetts Eye and Ear Schepens Eye Research Institute, has invented glasses for hemianopia patients that will allow them to see with a normal field of vision, despite their condition.
Peli’s peripheral prism glasses optically shift objects from the blind side of the patient’s vision to the seeing side, and alerting them to objects that they would not be able to see otherwise. The technology is simple, just high powered segmented prisms attached to regular eyeglasses, but the power is groundbreaking. Patients upper and lower visual fields can be expanded up to 30 degrees with these glasses.
In a recent multi-center study, a group of randomized participants from 12 U.S. clinics and one United Kingdom center were given the prism glasses to wear at home for four weeks and then were given sham glasses to wear for the same amount of time. The sham glasses were identical to the prism glasses except they only provided 2 degrees of visual improvement instead of 30.
The study, which was published in the journal JAMA Opthamology, found that more than half of the participants (64 percent) chose the real prism glasses over the sham glasses when asked which they preferred at the end of the eight weeks. The 36 percent who chose the sham glasses cited more visual comfort as the main reason for their decision.
Six months after the study, 41 percent of patients were still wearing the prism glasses on a regular basis and reported that the glasses greatly improved their field of vision and were helpful in obstacle avoidance when walking outside, in crowded areas, and in unfamiliar places.
Researchers who conducted the study concluded that Peli’s prism glasses provide a simple, very effective, inexpensive treatment option to improve the quality of life of hemianopia patients.