Essay on Eye and Dot

Submitted By lggabra
Words: 317
Pages: 2

This week in psychology we discovered that humans have blind spots. We tested this by drawing a dot on a note card and a different object to the right of the dot. Then we closed our left eye and stared at the dot while we slowly moved the card away from our eyes. About 4-6 inches away from your face it will seem as if the object to the right of the dot has disappeared, when in fact it has not, it just appears so. The object itself is way to the right of the fovea, but the physical blind spot in the human eye is on the left side of the eye. The fovea is the small, central region of the retina which contains only cones, and no rods. Because of this, optical activity at this site is greatest. This is also where our vision is the sharpest. The actual blind spot in the eyes of humans is created because the back of the eye, the retina, is full of sensor cells, also known as rods and cones. These sensor cells send out a signal through the axon, and the location of where these entire axons meet to form the optic nerve, doesn’t have any sensor cells. This creates a blind spot because the sensors can’t overlay the nerve bundle at that point on the retina. We also learned in our psychology class that octopi do not have a blind spot in their vision. This is because in vertebrate yes, the nerve fibers route before the retina, which blocks some light and create a blind spot where the fibers pass through the retina and out of the eye. However, in octopi eyes, the nerve…