Sixty-six-year-old Elsie Trinidad's only eye problem was nearsightedness. But last October, she noticed a black shadow at the bottom of her field of vision. She had no pain.
"I just ignored it for a couple of days until I realized something was wrong with my eyes," she said.
And when she saw her eye doctor, he found she had actually lost some vision, the result of a detachment of her retina from the back of the eye.
"I was astonished," she said. "I had no idea it was such a serious condition."
It was much more serious than floaters, which are clumps of debris that float in the liquid that fills the eyeball. They look like floating dust, dots, or strings and move if you move your eyes. They're not serious and increase with age. But a detached retina is serious.
The retina is a layer of cells around the inside of the eye that sends vision signals from the optic nerve to the brain. If it pulls away or detaches from the inside, you can lose vision.
Symptoms can be flashing lights such as sparkles, shooting stars or fireflies.
These flashes, combined with new floaters, may mean a retinal tear, which can lead to detachment.
"Within the first 24 hours, 48 hours, if you have a tear, you can laser it and create a scar around it and you're done," said Dr. Umar Mian, of the Montefiore Medical Center.
Tears can be fixed with outpatient laser treatments. Waiting longer than 48 hours to see the doctor increases the risk of permanent eye damage. There was a lesson in Elsie's small amount of vision loss.
"Any changes that I see, I know that I have to act on it as soon as possible," she said.
There are other treatments involving surgery on the eye for more severe tears. Migraine headaches can be linked to visual flashes, but these are persistent pinwheels, zigzag or shimmering lights that can go on for 15 minutes or more. Flashes from a tear disappear in a second.