Impaired vision and blindness are common. About 3.4 million people in the US are blind or visually impaired. Vision is usually measured by visual acuity charts, and normal vision is expressed as 20/20 ...

“From Brown to Evergreen: How Eye Colors Evolved” Your eyes may seem ordinary when you catch your reflection each morn ...

Eye color genetics is complex, with multiple genes from each parent determining a person's eye color. Scientists once believed a single gene controlled eye color, but research shows that more than 50 ...