New data suggests peripheral prism glasses can significantly improve patients’ ability to detect objects on the side of homonymous visual field defects (HVFD), for both those with and without left neglect.

Researchers investigated if patients with left hemispatial neglect and HVFDs benefit from peripheral prism to expand the visual field and improve obstacle detection. The study examined 24 patients with HVFDs, 10 of whom had left neglect. The patients viewed a virtual shopping mall corridor and reported if they would have collided with a human obstacle that appeared at various offsets up to 13.5° from their simulated walking path.

With the aid of the prism, patients were able to detect an obstacle in the controlled conditions of the virtual mall collision judgment task under steady central fixation. Detection on the side of the HVFD improved significantly with prism in both groups, from 26% to 92% in the left-neglect group and 43% to 98% in the non-neglect group.

Researchers conclude that peripheral prism may be helpful in clinical care of patients with left hemianopia and left neglect. They suggest that further study needs to evaluate neglect patients in free-gaze conditions after extended wear and also in real-world mobility tasks.