BIO 208 Lecture Notes - Lecture 25: Point Spread Function, Spread Betting, Visual Acuity
25 Feb 2018
School
Department
Course
Professor
Document Summary
In ny, legal blindness is defined as a visual acuity of 20/200 or less in the better or stronger eye. Measuring visual acuity: this visual acuity test, the snellen eye chart, measures how well you can see the differences between lines and spaces that make up letters, normal vision is defined as 20/20. A person with 20/50 vision can see at 20 ft what a person with normal vision can see at 50 ft. Spread function psf): psf is a technical term for blur. Instead we see a uniform gray when looking at a series of stripes. Measuring visual acuity: visual angle: we measure the visual angle using degrees. 60 minutes: the number of degrees of visual angle that an object covers on the retina depends upon its dista(cid:374)(cid:272)e f(cid:396)o(cid:373) the e(cid:455)e. a (cid:395)ua(cid:396)te(cid:396) at a(cid:396)(cid:373)(cid:859)s le(cid:374)gth (cid:272)o(cid:448)e(cid:396)s (cid:1006) degrees of visual angle.
