In today’s optical illusion challenge, a field of the number "27" hides a sneaky imposter. At first glance, it looks uniform, but only sharp eyes can spot the odd one out. Can you find the hidden “21” ...

Data on loss of visual field were collected at the time of application for the simulator test, leading to inconsistencies in the availability and recency of these perimetric results, with some ...

Optical illusions also help stimulate the areas of the brain responsible for visual memory and intelligence. These are simple tools that help test the ability ... see a word grid containing ...