What is the structure that controls the amount of light entering the eye

The iris (aka the colored part of your eye that surrounds your pupil). The iris will enlarge or dilate the pupil, depending on how bright or dark the environment is.

if you are on the computer you can not take a picture but you can upload one but i am not sure about phones but i'm pretty sure it's the but to upload one just click the paper clip looking thing/ link thingy thing and upload a pic

50% i think

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