One of the most dramatic experiments to perform is the demonstration of the blind spot. The blind spot is the area on the retina without receptors that respond to light. Therefore an image that falls on this region will NOT be seen. It is in this region that the optic nerve exits the eye on its way to the brain. To find your blind spot, look at the image below or draw it on a piece of paper:

o +

To draw the blind spot tester on a piece of paper, make a small dot on the left side separated by about 6-8 inches from a small + on the right side. Close your right eye. Hold the image (or place your head from the computer monitor) about 20 inches away. With your left eye, look at the +. Slowly bring the image (or move your head) closer while looking at the +. At a certain distance, the dot will disappear from sight...this is when the dot falls on the blind spot of your retina. Reverse the process. Close your left eye and look at the dot with your right eye. Move the image slowly closer to you and the + should disappear.

Answer:

Explanation:

★The External Structure of an Eye

The External Structure of an EyeSclera: It is a white visible portion. ... Cornea: It is the transparent, anterior or front part of our eye, which covers the pupil and the iris. The main function is to refract the light along with the lens. Iris: It is the pigmented, coloured portion of the eye, visible externally.

★optic nerve

optic nerveThe optic nerve carries signals from the retina to the brain, which interprets them as visual images.

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