It was previously believed that our pupil size was only affected by three things: light, focusing on nearby objects and ...

A pupil distance meter is a device used to measure the distance between a person’s pupils before they are fitted with glasses, in order to ensure the lenses are centred in the visual axis.

Researchers at Karolinska Institutet in Sweden have discovered a fundamental mechanism that affects the size of the pupil, ...

For more than a century, scientists have understood that three factors control pupil size: light, focus distance, and cognitive processes like emotions or mental effort. Now, researchers at Karolinska ...

Researchers at Karolinska Institutet in Sweden have discovered a fundamental mechanism that affects the size of the pupil, ...

In PD-82II digital pupil distance meter LED lamp eliminates troublesome lamp replacement and also makes battery life become as 3～4 times as longer than the older model and lever action becomes ...

Users of stronger optical inserts in particular complain of headaches after using Vision Pro. Sometimes changing the settings helps.

Make a note of where the top of pupil one's thumb is on the ruler in centimetres. And record the distance in the pupil's reaction times chart. Repeat the test five times for each pupil.