Rod+Cells+-+AR

= Introduction = The **retina** has two types of **photoreceptors**: **rods** and **cones**. Rods and cones work together to help you see colors and detail in different levels of light. Light passes through the **lens** and through the **pupil**. The light strikes the back of your retina where a layer of photoreceptor cells are. When light hits, the nerve impulses send a message is through the **optic nerve** to the **cerebrum**, which is the main part of your brain in the front and is the main place where actions of your daily life are. When the nerve impulse is sent there, it flips the image right side up and puts the images from both eyes together. Without rod and cone cells aligning your retina, there would be nothing to process in the cerebrum. Rods and cones are vital cells in order to see. = Structures of Eye = The front most part of your eye is called the **cornea**, and its a very thin, clear dome-shaped tissue. Behind the cornea is the **aqueous humor**, which is a clear fluid, and behind that is the lens, which focuses light so we can see near and far. A tube called the **hyaloid canal** goes through the **vitreous humor**, which is the main body of the eye, and connects the lens to the optic nerve. The vitreous humors walls are lined with the retina, which is filled with the two photoreceptors, rods and cones. The optic nerve is connected to the cerebrum, where the picture is received and processed.



= Difference Between Rod and Cone Cells = Rods and cones are both photoreceptors cells in the retina. Rods let you see black and white, and are in use in dim lighting. There are about 120 million rods in the retina. Rods are very sensitive which makes them responsive to a single photon of light, but they would only make a gray, blurry image. Details and color come from cones. There are approximately 6 million cones in the retina. Both rod and cone cells have special jobs in order for us to see.



= Eye Problems = A common eye problem is **cataracts**. They form slowly and painlessly, but they become a major issue when they become larger. Cataracts form on the lens of the eye, and can make vision blurry or cloudy, but they can be removed by surgery. The lens of the eye is made up of protein and water. As you get older, the protein in your lens can get bunched up. The lens of the eye is a lot like the lens of the camera so, as you can imagine, it is hard to see if you have a cataract. You can be more likely to get cataracts if any of the following, but not limited to it, implies to you. Diabetes, obesity, smoking, previous eye injury or surgery, great alcohol consumption, or family history. To prevent cataracts, regular intakes of vitamin E are recommended.



Color blindness is another vison problem that's often hear of. Color blindness is a problem with the cones in your retina. There are three different types of cones: **L-cones**, **M-cones**, **S-cones** and they are responsible for a different color in different wavelengths of light. L-cones detect long wavelengths of yellow and red. M-cones are responsible for medium wavelengths of green. S-cones handle short wavelengths of blue. Color blindness occurs when one or more of the three types of cones are missing from your retina. Red green color blindness is the most common. Color blindness is usually **hereditary**, which means its a gene passed down in the family. It can also be caused by incidents that have affected your eye. = Conclusion = Rods and cones are a very important part of the eye. Without them, we wouldn't be able to see many magnificent things, like rainbows or sunsets. Eyes are a very delicate and complex organs that need gentle care, because your vision is precious. Be greatful that you have all your L,M,and S-cones so you can see everything in its full potential. If your vison starts to gray or becomes cloudy, talk to a doctor about it so they can correct it. Take care of your eyes by consuming vitamin E.

toc = References =

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