Physiological/Day Blind Spot

The actual blind spot is caused by the lack of optical receptors were the optic disk is located. My question is if the blind spot if a fixed size throughout the field of view. In a study group, we are split with two possibilities. One, the blind spot size increases as the distance from the eyes increase. So it is like a cone projecting out. Not a large degree but some increase in size. The second idea, the blind spot seems to get bigger only because the apparent size of an object gets smaller as the distance from the viewer increases. If you could help solve this debate and also provide some published info that we could discuss and possibly demonstrate in a classroom environment. Thanks you!!!

[John C Hagan III, MD, FACS, FAAO]

The size of the blind spot will increase in size getting larger the further the test is conducted from the eye (your proposition #1).

These are some interesting websites:

http://www.blindspotmapping.com/home.html

http://pt.wkhealth.com/pt/re/acop/abstract.00043481-200606000-00014.htm;jsessionid=HzNRhhqDsZq8QMnjk38yQhhy7CPJKypD8GqQnTlCVdFH9XkMfXnB!-809317659!181195629!8091!-1

http://www.opt.indiana.edu/riley/HomePage/Tanget_Screen/Text_TangetScreen.html

JCH III MD