posted 2012-03-07 20:53:34

It’s ALIVE!

An exploration of human anatomy, this week: Are You Blind?

Tara Bohensky, Staff Writer



Yes. You are blind. Technically, anyway, but more of that in a minute. I’d like to make some introductions before we get to the good stuff. “It’s ALIVE”, will be making regular appearances in forthcoming editions of the Hunter Envoy. It’s going to be all about you, or more specifically your body, its blood, guts, organs and all.

Now, it’s time to get up close and personal with the windows to your soul. Firstly, your eyes don’t physically serve as portals to anything, and contrary to popular (if ignorant) belief, you cannot actually see into your brain if you look hard enough. However, eyes do serve as a looking point to the inside of your eyeball, which is an orangey-red color, and looks like the bright fireball of setting sun on summer evenings. In fact, the inside of your eyeballs would be more aptly named ‘windows to the trunk’-that is, the main center of your body. Diseases that occur deep within your viscera, such as diabetes and hypertension can be diagnosed by assessing the condition of the blood vessels inside your eyeballs.

Did you know that you can’t actually see color in a dark room? Inside your eye, there are two kinds of receptors, called rods and cones. Rods cannot produce color images. They are the receptors that are active in a dark room, or at night, and can only see in shades of gray. Cones, on the other hand, see color. Three colors, to be exact: they can see blue, green and red. It is the combination of impulses from a few different cone cells that allow you to see the world in its full color spectrum. People who are colorblind either lack completely, or have a severe deficiency of one of the three types of cone cells.

Next time you accidentally (or not), bang into that mammoth of a man in the Walgreens parking lot, and he yells “Are you blind?!”, you can answer a confident yes, and not be lying at all. Everyone is blind, because everyone has optic discs. The optic disc is the place on the eyeball at which the optic nerve originates. At this location, none of the rod and cone receptor cells are present; therefore no light signals are transmitted from this area, creating a blind spot. If you don’t believe it, try it out yourself.

Hold your paper or iPad about thirty inches away from your face. Close your right eye, focus on the plus sign, and slowly bring the paper towards yourself. At some point between three and eighteen inches, the circle will disappear. That’s your blindspot.

The part of your eye that focuses light, and allows it to reach the optimal spot on your eyeball, the fovea centralis, is the lens. It is a fibrous ball of jelly that lies right behind your iris, and it changes shape with the intensity and angle of light passing through it. It is a delicate ball of jelly, however, and a whole host of bad habits or ghastly luck can damage it, thereby obstructing vision by not allowing light to pass through it properly, if at all. The good news is that it’s relatively easy to replace a real lens with a surgically implanted one that can dramatically improve vision.

Studies have shown that women live longer than men do. The question has always been, why? Possibly, it is our penchant for tears. Like dog spit, tears contain an antibacterial agent known as lysozyme. When we cry, that cleanser washes over the eye, killing any pathogens that might try to use the eyeball as an entranceway into the body. More crying means more antibacterial washes, which in turn, leads to a cleaner, healthier inner environment. Try it guys, it won’t kill you.