The blind spot is ____________________.
 |
formed by the optic disk; |
 |
caused by the absence of visual receptor cells; |
 |
caused by the collection of axons leaving the eye; |
 |
located at the back of the eye; |
 |
all of the alternatives are correct; |
[Review Part 1 of the tutorial] [Review Part 2 (Matching) of the tutorial]