Glaucoma is not one disease, but a group of diseases that can cause permanent blindness if left untreated. Just as there are different types of glaucoma, there are different treatments.
Glaucoma robs people of their vision. It happens when fluid builds up in the eye, causing so much pressure that it kills cells in the optic nerve. Mary Hyman was diagnosed with glaucoma more than a decade ago.
"It was something that came on, and I was not aware," said Hyman.
Hyman knew something was wrong when she was playing peek-a-boo with a child.
"And I did one of these, and I said, that left eye is blurry," she said.
There's no cure for glaucoma, but it can be controlled by reducing the pressure in the eye. Dr. Eric Fleischer.
"There isn't a magic number. That's the tricky part," said Fleischer.
The right pressure is different for every patient. And so is the treatment. The first course of treatment is usually with eye drops.
"We give the patient a drop, we measure their pressure, and we see if it lowers the pressure. If it won't, then the next step is laser surgery," said Fleischer.
The type of treatment depends on the type of glaucoma the patient has. Dr. Alan Robin says it can also depend on where the patient lives.
"Some drops need to be refrigerated and there's no way in some places like southern India where it's hot, hotter and hottest, or in tropical areas such as equatorial Africa, where you can keep things in refrigeration all the time," said Robin.
Cost can also be a barrier to treatment. Dr. Rengaraj Venkatesh is with the Aravand Eye Hospital in India.
"In India, when someone seeks health care, they don't come alone. They come with at least one family member. So the cost involved in getting to the hospital is also expensive," said Venkatesh.
But for those who can get treatment, glaucoma patient Mary Hyman says this:
"When you get your physical, get your eyes examined. Even though you might not think you have a problem. Get your eyes examined," she said.
Hyman is grateful that she is being treated for her glaucoma. Meanwhile, the World Health Organization says glaucoma is an emerging priority because the number of cases is expected to increase as more people the world over live longer.