In the specialized fields of ophthalmologyand optometry, doctors measure sight by having you focus on a central point while keeping your head still. You’ll also be able to see above and below the ...

This is an image to demonstrate visual 'crowding' and test peripheral vision. Ensure that the red dot in the centre of the image is at eye level and focus on it. While holding your focus on the red ...

This is an image to demonstrate visual 'crowding' and test peripheral vision. Ensure that the red dot in the centre of the image is at eye level and focus on it. While holding your focus on the red ...

We were unable to process your request. Please try again later. If you continue to have this issue please contact customerservice@slackinc.com. A 66-year-old man was seen in the glaucoma clinic at ...

In a new optical illusion, dots appear purple in central vision but blue in peripheral vision. Here's how it works.