What about all these other parts of the eye? What do they do?
&gt;&gt; Well, there's a lot going on here. So, let's talk about it. right here, we have
this clear protective membrane and that's called the cornea. And the eye is
pretty important so, its job is basically just to protect everything that's
going on inside.
&gt;&gt; And how about the blue part here?
&gt;&gt; Well, that's the colored part of our eye. That's called the iris. And, in
addition to being very pretty, it's a muscle that constricts or dilates to
change the amount of light that's let in through this guy here, and that's
called the pupil. And when it's dim, you'll notice that your pupils tend to be
pretty big. Versus when it's pretty bright out, they tend to be pretty small.
Because they don't need as much light.
&gt;&gt; Then what about this guy right here?
&gt;&gt; Right. That's the lens. Remember how before we were talking about how the light
gets bent when it enters the eye?
&gt;&gt; Uh-huh.
&gt;&gt; Well, the lens is what does that bending, that focusing, to make sure that the
light enters and is focused onto the back of the retina.
&gt;&gt; And when it hits the retina, that's where our rods and cones are, right?
&gt;&gt; Yeah, exactly. Those rods and cones are called photoreceptor cells. And so,
this retina actually contains many layers of these rods and cones.
&gt;&gt; And so, rods, photoreceptor cells, photo means light, receptor means to
receive. They actually are sensitive to primarily black and white vision, and
they help us to see at night time.
&gt;&gt; So then, does that mean the cones help us see color?
&gt;&gt; Exactly. And there's actually three different types of cones. Some are
sensitive to red light, which is a long wavelength. Some are sensitive to green
or medium wavelength light. And some are sensitive to blue, shortwave length
light. So, these are used for color vision.
