SAN DIEGO, Calif. -

Jill Herndon knows that regular eye exams are very important.

She has a family history of glaucoma and was diagnosed with the disease herself at age 40.

"It's always a scary thing to contemplate losing one's vision," said Herndon.

Jeffrey Miller doesn't have a family history of glaucoma, but the pressure in his eyes began to increase in his 30's, a warning sign of the disease.

"I don't take my eyesight for granted," said Miller. "I'm one who really, really appreciates what I've been able to maintain."

Glaucoma affects more than 70 million people around the world, making it the leading cause of irreversible blindness. Experts say glaucoma often goes undiagnosed until it becomes severe.

Dr. Robert Weinreb from the University of California San Diego School of Medicine and his co-authors studied more than a decade of medical literature on how to detect and treat the two types of glaucoma -- open angle and closed angle.

"The eye is like a sink, it has a faucet and it has a drain," said Weinreb. "In one of them, the drain is blocked internally and one of them the drain is covered up and blocked on the outside."

This increases pressure in the eye and can damage the optic nerve.

Regular eye exams can catch problems early, but researchers say family doctors can also play a role.

"Primary care providers could have a major role in detecting, recognizing and referring patients who are at the highest risk for developing glaucoma," Weinreb. "We single out those individuals who have high eye pressure, intraocular pressure, individuals who have a family history of glaucoma and then there are certain ethnicities that are at highest risk for glaucoma, particularly those of African ancestry and also Latino ancestry."

Medications are commonly prescribed to reduce the pressure from fluid buildup. There are also several different surgical options, including newer minimally invasive surgeries that may be safer and may have fewer complications for patients.

Researchers say early detection and treatment are critical.

"Regardless of whether the patient does not yet have glaucoma and you are treating to prevent glaucoma or the patient has existing glaucoma and you are treating to prevent progression of glaucoma, early treatment can make a difference," said Weinreb.

Both Herndon and Miller continue to work with Weinreb to keep their eye pressure in check.

"Vision is everything," said Herndon. "It's your primary sense, it's how we initially take in our world."

Their advice for everyone -- be vigilant about your vision.

"Get your eyes checked just as early as you can and as thoroughly as you can," said Miller.

To learn more about glaucoma, click here.