Pupil shapes vary widely across the animal kingdom, from the W-shaped pupils of cuttlefish to the bar-like pupils of goats.

The dark part of your eye is called the pupil. Pupils can grow or shrink according to different lighting conditions. Other factors, such as drugs, can also affect pupil size. Read on to find out which ...

Medications, trauma, and medical conditions can cause miosis or constricted pupils. Seek emergency help if you experience signs of a stroke, like confusion or trouble speaking. A healthcare provider ...

The black circle in the center of your eye is your pupil. It changes size thousands of times a day. When you're in dim light, it gets bigger to let more light in. When you're in bright light, it ...

The creation of a bionic eye that mimics the widening and shrinking of the pupil may bring us one step closer towards helping people with certain visual impairments. Light enters the eye via the pupil ...

Pupils, which are the dark dots in the center of your eyes. They shrink or widen to control how much light gets into your eye. During the test, your doctor will make sure your pupils are in the right ...

Opioids usually make a person’s pupils constrict. This is when the black part at the center of the eye gets smaller, reducing the amount of light that gets inside. Typically, pupil constriction ...

Nocturnal animals tend to have proportionally bigger eyes than humans do. They also tend to have pupils that open more widely in low light. So, at the outset, nocturnal eyes gather more light than ...

What do an orgasm, a multiplication problem and a photo of a dead body have in common? Each induces a slight, irrepressible expansion of the pupils in our eyes. For more than a century scientists have ...