<p>this seems kind of silly to make a thread for, but i really need help on a question on a lab and no one seems to know. OK so if you put the tip of ur index finger in the corner of ur eye (near ur nose) and apply some pressure, u see a dark shadow. the question asks WHY you see this shadow?
Im thinking it has to do with photoreceptors - rods and cones - but im not sure how. give a kid some help? id really appreciate it. thanks for anyone that can help!</p>
<p>Probably because your eye can only discern the fact that something is blocking light transfer without seeing the color or reflection at that distance and in that section of the eye.</p>
<p>oh wait i forgot to mentioned ur eyes r closed during this experiement. does that change anything?</p>
<p>Blood Flow?</p>
<p>If the eyes are lightly closed, that means that everything except the distance part probably remains true. The cones can tell that something is blocking the light, and the image produced is the reflection of the light on the object and its color. The eyelid is too thin to block out light, so when one closes the eyes, one sees red. However, the thickness of the finger can block light transfer, and as a result there is a shadow picked up where the light is not being transferred.</p>