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 ...

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 ...

The mesmerizing colors of human eyes—from deep browns to vibrant blues, subtle greens, and rare ambers—result from intricate genetic factors that influence melanin production in the iris. This same ...