00:01
This question is asking us to think about which reactions occur when a person is trying to focus on a distant object.
00:09
Specifically, it wants us to think about pupils and constriction and dilation, the tension in the ciliary zone, and the lens becoming more concave or convex in order to focus the light.
00:24
So let's think about the ciliary zone and the lens first.
00:29
When we're looking at a distant object, we are going to be looking at rays of light that are coming pretty much horizontal to the eye.
00:40
And what that means for our purposes is we do not want a lot of scattering of light.
00:45
So we actually want this tension to increase like we have highlighted in red over here.
00:51
So as the light passes through, it goes in a pretty much straight line through the lens.
00:57
So that means that we're going to have more tension in the ciliary zone and the ciliary layer, and that's going to pull on the lens, making it less convex.
01:08
And then with regard to the other part of the question, which is asking us to think about whether pupils expand or contract, we want to think about how much light we're going to need in order to see something that's far away versus something that's close up.
01:28
And when we are looking at something far away, we do require more light...