Your pupil's have to adjust from the light to the dark so your pupils will get bigger in a dark room.
Your pupil expands in the dark in order to obtain more light. Your eyesight is interpreted by the brain with light signals, when it is dark your pupil expands to grab as much light as possible.
The iris controls the amount of light entering the eyes through pupil. When the surrounding is extremely bright, the iris contracts the size of pupil. This decreases the amount of light entering the eye. This is why when we are suddenly exposed to bright light, the eyes blink and in meanwhile, the iris contracts.
When the eye detects bright light, the iris expands causing the hole at its centre (the pupil) to shrink in size. The brighter the light the smaller the pupil becomes. This happens because, in a dark place, the eye needs to take in as much light as possible to see better so the pupil expands; in a light place, the eye could be damaged due to over exposure to light so the pupil shrinks. The scientific word for "shrinks" is "contracts"
The light receptors in the eye are called cones and rods. Cones are responsible for color vision and detailed vision in bright light, while rods are more sensitive to low light levels and are important for night vision.
When exposed to a bright light, the pupil of the human eye will contract. This action allows less light to come in contact with the lens.
It is difficult to see once entering a dark room after being in bright light because the pupils adjust how much light goes into the eye. In the sunlight, the pupils are tiny. In a dark room, the pupils need a few seconds to adjust to open wider.
The Iris controls the size of the pupil to control the brightness of the light that's allowed to enter the eye. This is a protective measure when the light is too bright and it also opens the iris in low light situations to allow the eye to see more. Well, the iris changes the size of the pupil so when you are in bright light your pupil will get smaller because the eye will absorb all light striking it. However, when you are in a dark room or place your pupil will get bigger/wider because it has no light to absorb it so your eye wants light. For example think of the pupil trying to look for light so it has to get wider!
It gives off a bright white light (glowing manner) that shouldn't be looked at with the naked eye.
To function efficiently the eye needs bright light. For maximum efficiency the eye needs light to be at a wavelength of 0.555um. The eye can perform efficiently in the dark at a wavelength of 0.510um, but there is a weakness in color.
When bright light is shined into the eye, the circular muscles of the iris contract while the radial muscles relax. This response, known as the pupillary light reflex, causes the pupil to constrict, reducing the amount of light that enters the eye. This mechanism helps protect the retina from excessive brightness and enhances visual acuity in well-lit conditions.
Afterimage is a visual phenomenon that happens when you see a lingering image after looking at a bright light. This occurs because the light overstimulates the retina in your eye, causing a temporary image to remain even after you look away.