It all started when a 22-year-old woman in the United Kingdom thought she was going blind in one eye. It was a strange sort of blindness though. During the day, both of her eyes worked fine, but at night, one began to fail her. Doctors were perplexed. Then, a 44-year-old woman also came forward reporting the same frightening symptoms. Doctors couldn't figure out what it was for the longest time.

When it first started happening, it was only a couple times a week that they'd experience it. Then every night they started to lose vision in one eye, and then the other started going as well. Doctors were disturbed by both the cases and set to work trying to figure out what was wrong.

The problem with trying to find the right diagnosis is that nothing seemed wrong. MRIs came back clear, vision tests were fine. Everything they checked for seemed to be perfectly normal with both women.

One of the women was prescribed blood thinners, as vision loss in one eye can be indicative of a stroke. It can also be a sign of a compressed optic nerve. Neither women, however, seemed to suffer from either affliction. After further investigation, the doctors figured out what was causing their blindness, and it's something everyone should read.