Understanding Visual Field Loss

Seminar | November 18 | 11:10 a.m.-12:30 p.m. | 489 Minor Hall

 Eli Peli, Harvard Medical School

 Neuroscience Institute, Helen Wills

Could we develop more effective field expansion devices if we better understood the nature and impact of field loss? No proof of that, but I’d like to think so. Simulations have been a major tool in trying to understand the nature and impact of the loss. Most simulations of field loss found in textbooks, websites, and scientific papers are wrong; they do not represent what patients perceive. I’ll argue that the wrong simulations are the result of: the difficulty in representing the dynamic visual process with static images; the difficulty in illustrating lack of vision; and confusing the field diagram with the perception. The wrong simulations and misunderstanding they promote persist due to paucity of attempts to verify the simulations, which would have rejected them. We will consider all these issues with regards to the many types of field losses, including: Retinal field loss (photoreceptors or ganglion cells loss); physiological (nerve head) scotoma; acute monocular vision loss; chiasmal and post chiasmal lesions; device scotomata (field obscuration and optical scotomata); binocular scotomata and the interaction of scotomata with eye movements. I will conclude with novel illustration of the appearance of pericentral scotomata and the impact of saccadic “suppression” on the perception with such scotomata despite substantial spatial distortions.

 nrterranova@berkeley.edu