fA team of researchers are working on new glasses with prisms to expand the vision of patients with peripheral vision loss.
Patients with peripheral vision loss are prone to collision with other pedestrians in crowded areas like shopping malls and bus terminals. To be able to develop glasses to expand the vision of the affected individuals, the researchers need to find out in which direction does the collisions actually occur.
The researchers studied the angle of highest collision risk in patients with peripheral loss of vision. For developing the collision risk model, it was assumed that pedestrians were moving in all directions at all the possible locations with a moderate walking speed, which is appropriate for open space environments like parks and malls.
Study On Patients With Retinitis Pigmentosa
The investigators involved 42 retinitis pigmentosa patients that have limited vision for the study. The team compared the mathematical model prepared in association with peripheral vision loss and collision risk with the study participants.
It was found that the risk of collision with low-bearing angles were very low. However, the risk was observed to be higher at lateral retinal eccentricity at an angle of 45 degrees. If the prism devices are designed to expand the vision at 45 degrees it might help reduce the risk of collision in patients with limited vision.
It is also noted in the study that the prisms currently available in the market cover an eccentricity of 30 degrees which is less likely to support people with peripheral vision loss.
Developing Eyewear For People With Limited Vision
The collision risk in people with peripheral vision loss is high at 45 degrees from the person's walking path, noted Eli Peli professor at Harvard Medical School. "This means that any visual-field expanding device will be most effective if it can cover that angle," noted the researcher, in a press release.
Peli, the study's lead author, and team are aimed at developing prism-based eyewear that would focus the objects at 45 degrees. The prism used would be designed to bend the light from that angle to the areas of the eye that are functioning well.
Patients That Could Benefit From The Eyewear
People with retinitis pigmentosa, choroideremia, Usher syndrome, advanced stage of glaucoma and patients that lost vision in left or right half of the eye as an outcome of stroke, trauma or brain trauma are likely to benefit from the eyewear, which is currently in making.
The study is published in the Journal of Vision.