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 ...

Photophobia is an abnormal sensitivity to light. It is associated with dry eye disease, migraines (severe, recurrent headaches), and traumatic brain injury (TBI). Research has found that people with ...