how come when you turn on the light your pupils get smaller and when you turn the light off ur pupils get big?

Answer 1

You pupils on average are about 7mm in diameter, but will close up (not completely!) in bright light to protect the retina, the part of the eye the 'receives' the image. The pupil wil also dilate (open up) to receive more light in low light sitiuations, so you can see more. This is called dark adaption, and can take several minutes to dilate to the maximum.

Answer 2

to let more or less light in. On the back of your retina there are two types of light sensors. Called Rods and Cones. I can't remember which one is which, but one has better color reception and the other is better for low light reception. The color receptors have a higher concentration in the middle of your retina and the low light receptors are more prevelant to the sides. So when your pupil gets bigger in low light or darkness, more of this outer receptors start to work.

Ever try looking directly at something in a dark room (not pitch black, but very very low light). You can't see the object, but if you look just to the side of it you can see that object in your side vision. That's because the low light receptors are now 'seeing' that object....

Answer 3

PROTECTIVE job of iris muscle to make pupil hole smaller is called CONSTRICTION, and it is designed to keep too strong or too much light from entering the eye.

DILATION of pupil hole or iris muscles helps to let maximum light entering.

All this happens due to light, yes, but these same iris muscle reactions that change the pupil diameter can happen as a result of the fight-flight mechnism (dilation during more stress and epinephrin-adrenalin) or during drugs. Pot, belladona (usually eye drops) and cocaine can all make iris muscle respond, the pupil hole dilate.

Answer 4

t ocontrol the amount of light that enters ur eye and hits the retina. in a bright room, pupills get smaller to limit light entry and in dark room, it gets bigger to ensure a greater amount of light entry. these process allows optimal conditions for the eye to process its surrounding

Answer 5

when you turn on the light the puplis constrict because too much light would damage your eyes, and when you turn off the light your pupils expand so that more light can enter your eyes so you can see better.

Answer 6

Firstly, your pupils are fixed, meaning they stay they same size. However their function is to allow light to enter. It is the iris of the eye which RESPONDS to light intensities.

Answer 7

As you know,we cannot see either in too much light or in too little light.
so,when too much light is available,the pupil contracts itself so that only the required amount of light passes through it.

When there is too little light,the pupil expands itself allowing maximum light available.

Answer 8

Very good question with very good answers. So since my answer would be redundant or a total combination of all given answers, I will just throw some trivia in: Cats can see in total darkness? (True or False)
FALSE Nothing or no one can see in TOTAL darkness. Cats just have the ability to see in the dimmest light situations. Their eyes are some of the most sensitive to low light situations.

Answer 9

is a reflexed movement of the muscles. this is to ensure that the eye receives always the right amount of light to see properly. If you think about it if the light is too strong hurts you eyes and you can't focus.

Answer 10

It adjusts the white balance of the vision by limiting the amount of light into the retina.