Courtney C Post #1 February 17, 2010

Review of Class
1) There is a brain/eye/ear quiz on Feb. 24
2) The Unit Exam is on Thursday Feb 25. It is on the nervous system
3) We did a recap of the eye. We discussed what acommodations your eye does.
4) We learned about the parts of the eye and the function of each part.

Thoughts on Material
I thought that this section on the eye was very interesting.  It is interesting learning about how you see things and what is going on in your body during a simple task like looking at something. The way the eyes works and the roblems that can happen in it is very interesting.  We covered alot about the eye the only thing we did is color.  Why do we have certain colors of eyes and does it sertve any purpose.  I am very interested to understand why peoples eyes are different colors and why eyes are different colors anyway. why do people have colored eyes?

Above and Beyond
I used wikipedia at this link http://en.wikipedia.org/wiki/Eye_color and i verified my findings with this link http://www.eyecarecontacts.com/eyecolor.html.  I found out that the color of your eyes is genetic.  You often get the same color of eyes as your parents.this is what i found out about eye color: Brown eyes, blues eyes, and green eyes. These are the "standard" eye colors, but we've all seen people with even different eye colors. There's also gray, "hazel", a mixed brown/green/blue, golden brown or amber, even violet. Many children a born with non-descript gray eyes and some become blue, some brown. 

Eye color is determined primarily by the concentration and distribution of melanin pigment on the iris fibers. The iris is located inside the eye, between the cornea (front most surface) and the internal crystalline lens. The hole in the middle is called the pupil and it changes size to regulate the amount of light entering the eye. If the iris contains pigment on both the front and back surface, the incident light that reflects off the iris is brown. Sometimes there is little or no pigment on the front surface. The light interacts with the gray iris fibers and the iris stromal cells and reflects as blue. The size and spacing of the fibers and stromal cells determines the "blueness" or "greenness' of the reflected light. Although the majority of irises have similar pigment density on the back surface (called the iris pigment epithelium), some people have less and that allows for some reflection from the retina in the back of the eye. The retina reflects red from the network of blood vessels contained within its structure. This is also what causes the red reflex in the iris pupil seen in photographs taken with a flash. The red color interacts with the blues and browns to create aqua and violet iris colors. There's a rare genetic condition called albinism in which those individuals do not have pigment on the back of the iris and their iris color appears pink. Sometimes, the pigment from the back surface “rolls” up onto the front surface right at the pupil border. This results in a brown ring around the pupil, which can look quite unusual in an otherwise “blue” eye.