| an eye is an amazingly complex and delicate | | | | would be the area that receives the signals of the |
| structure that really is really fascinating to look at | | | | object you are concentrating your gaze on. |
| in detail. It is amazing to think that these small | | | | Behind the retina, and in front of the rear sclera, |
| structures are able catch and help process the | | | | is the choroid. |
| environment around us with such acuity and | | | | The choroid is a darkly pigmented layer that |
| clarity. | | | | absorbs excess light that has been taken in. The |
| The structure of the eye is pretty neat when | | | | choroid is a very important structure because it |
| looked at. First the enveloping membrane of the | | | | helps to sharpen the incoming images by |
| eye is called the sclera. It is a rather firm outer | | | | removing any excess light that would blur the |
| layer and is seen as the white areas surrounding | | | | image. It is like when you step out of a dark |
| the pigmented iris. The cornea is like the sclera in | | | | room into the sunlight. Until your eyes adjust, |
| that it acts as an outer cover for the eye, | | | | there is a bleaching effect where you cannot |
| however it is clear allowing for the passage of | | | | process images well due to the excess light and |
| light. Inside the cornea we have the aqueous | | | | the high activation of the rods in your eyes. The |
| humor. This is a jelly like substance which acts as | | | | choroid helps to remove some of the excess light. |
| a buffer between the cornea and the lens/iris. | | | | Connecting the retina to your brain is the optic |
| The iris is the colored part of the eye. Its main | | | | nerve. The optic nerve collects all the information |
| function is to constrict and dilate to adjust the | | | | from the rods and cones in your retina and sends |
| amount of light that passes through to the | | | | the signals to your brain to be processed into |
| nerves. The lens is pretty much exactly what it | | | | images. |
| sounds like. It is a lens that changes its shape to | | | | An interesting fact about the human eye is the |
| adjust the focus of the images you are seeing. | | | | blind spot. We all have it and it isn't some kind of |
| Making up a large part of the eye is the vitreous | | | | disease or mutation. The blind spot is actually a |
| humor. This is very much like the aqueous humor | | | | part of the retina called the papilla where there |
| in that it is a jelly like substance that is important | | | | are no rods or cones because it is the area |
| in giving shape and some rigidity to the eye. It | | | | where the optic nerve is attached. Because there |
| pretty much fills the entire inside area of the eye. | | | | aren't any rods or cones it creates a blind spot in |
| Lining the inside of the back of the eye is the | | | | your vision. The reason we do not see a blind |
| retina. | | | | spot normally is because our brain helps to filter |
| The retina contains rods and cones which serve | | | | out this spot by compensating the area and filling |
| as an agent to process the incoming light into a | | | | it in. A quick test can be done to find your blind |
| signal which the brain can process into an image. | | | | spot. Hold up two pens in front of your face. |
| In the retina is an area called the fovea which is a | | | | Focus your gaze on one that is directly in front of |
| depression in the retina containing a very high | | | | you and slowly move the other to the outside. At |
| amount of cones and rods. Because of the | | | | one point the pen or part of the pen should |
| densely packed receptors, the incoming light that | | | | disappear. That is where your blind spot is. Neat |
| hits the fovea is processed with the highest | | | | isn’t it? |
| resolution and clarity. In other words, the fovea | | | | |