Alright, everybody. Let's take a look at this example together. It says that glaucoma is a condition where the optic nerve is damaged due to increased internal pressure in the eye. Increased pressure inside the eye pushes on the retina, causing the tissue to die and vision to become patchy. One cause of glaucoma is a buildup of excess fluid in the eye.

Based on their properties, which fluid of the optic components is more likely to build up? Remember the retina is running all the way around the back of the eye here, and we have the optic nerve here. So to answer this question, the first thing I want to do is label my optic components. First off, we have the vitreous humor.

And remember the vitreous humor, shown here in pink, is this clear gel-like substance that's really filling up the majority of the eyeball. Remember the eye I described as this inflated soccer ball, and this vitreous humor is doing a lot of that inflation, filling it up. Now as I look at this, I see the vitreous humor is right up against the retina and the optic nerve there. So I'm kind of tempted to say that's going to be my answer, because if something's pushing on the retina, the thing that is pushing on it has to be the vitreous humor. But before I say that's my answer, let's see what else we got.

We also have here the lens. Now the lens is this, you know, hard but flexible structure. It's not a fluid. It's not going to be that. And then we have the aqueous humor.

And the aqueous humor is this liquid that's produced in the ciliary processes, and it fills up the front of the eye. And we said that it was produced, you know, sort of back here in the ciliary processes, and then it flows forward very slowly and actually drains out of these sinuses here in the eye. So as I look at this altogether, well, yes, the vitreous humor has to be the thing that's actually exerting the pressure. If you remember, we said the vitreous humor is a gel, and it's produced during fetal development, and it just stays there your entire life. So it doesn't seem likely that you're going to be getting more vitreous humor.

We said that doesn't really happen. What could you get more of or too much of? Well, you could get too much aqueous humor, because this aqueous humor is always being produced and sort of very slowly flowing forward and draining out of the sinuses there. And in fact, in a practice problem previously, we talked about what might happen if these sinuses get blocked, and that could increase pressure in the eye. Yes.

The thing exerting the pressure, actually pushing on the retina back here, will be the vitreous humor. But the reason it's going to do that is that you're getting too much aqueous humor up here in the front. Alright, therefore I feel very good saying that my answer is the aqueous humor. Alright, practice problems to follow. I'll see you there.