So we can see =]
Though i believe you meant to ask 'how'? They are basically just holes that allow light through
because when it it is bright like when somebody shines a torch in your eyes your pupils get smaller to stop all the bright light getting in your eyes so it won't damage your eyes and when it is dark like at 12:00 at night and you turn your light off your pupils get bigger to try and find some light it can let in to help you see better in the dark!!!
it is to help let as much light into your eyes as possible so you can see the best you can. this is why our pupils enlarge in the dark
the hole in the front of a camera can be made bigger or smaller to control how much light gets in. Your eyes work in a similar way. To much light can damage your eyes, so your pupils get smaller when it is very bright and in dim light your pupils get very bigger to let more light in
No; the change in the size of your pupil is an involuntary action, meaning that it happens without you thinking about it. The size of your pupils adjust to stimuli, such as bright light. If a bright light was shined in your eyes, your pupils would get smaller in order to let as little light in as possible. Reversely, if you're in a dark room, your pupils will get bigger to let in as much light as possible.
Your eyes see different brightness levels in various lighting conditions because they adjust to let in more or less light. In bright light, your pupils get smaller to let in less light, and in dim light, they get bigger to let in more light. This helps your eyes adapt to different levels of brightness.
No, they become smaller (constrict).The pupils become larger (dilate) to let in more light. The bright headlights would cause the eyes to let in less light, which means you will not be able to see anything clearly except those bright lights. You are "blinded" until your eyes adjust again, and by that time you may have veered off the road or had a collision.
No. Normally human eyeballs have their pupils behind their iris so that the eye can adjust to light but fish eyes have their pupils protruding through the iris so that it cannot adjust its eyes to light.
The pupils get larger. Pupils take in light and if it is dark, there is not much light if there is any at all. The pupils grow larger to take in as much light as possible. If the hole is bigger, more light can come in faster.
Cat's pupils can change shape depending on the amount of light they are exposed to. In low light conditions, their pupils dilate to let in more light, appearing larger and rounder. In bright light, their pupils constrict into vertical slits to reduce the amount of light entering their eyes.
It typically takes about 20-30 minutes for your eyes to fully adjust to the dark. During this time, your pupils dilate to let in more light, allowing you to see better in low-light conditions.
When light come into your eye your pupils will get smaller. In a dim or dark room your pupils will enlarge to let in more light so you can see. Also some drugs will make your pupils smaller, or when your high they dilate.
Pupils constrict in response to bright light to reduce the amount of light entering the eye and protect the sensitive retina from potential damage. Conversely, pupils dilate in dim lighting conditions to allow more light into the eye for improved vision in low-light environments.