"Far Peripheral Vision", and "Negative Dysphotopsia"


Far peripheral vision

 "Far peripheral vision"  is at very large visual angles (above 60 degrees), and it appears to be a visual region where there has been very little direct research. A recent review summarizes the information that is readily available: Simpson MJ. Mini-review: Far Peripheral Vision. Vision Research 140C (2017) pp. 96-105 (a version can be downloaded from the Downloads page).   The topic is included on this website because dark shadows ("Negative Dysphotopsia") are occasionally seen by some users of intraocular lenses (IOLs) in the far peripheral vision region. Researching this has led to the new questions that are discussed in the review paper. One basic question is how the limit of vision varies with age and refractive error. A limiting visual angle measurement of about 105 degrees dates from 1915, but there do not appear to be any population studies of this parameter, and modern test equipment only goes to 90 degrees at most. What if there happens to be an unexpected connection to myopia development, for example, but there are no data so nobody has noticed...