CHARLOTTE, N.C. — Three million Americans have glaucoma, an eye condition that causes a slow loss of vision, but half do not even know they have it.
Glaucoma is often called the "silent thief of sight" because people will not notice symptoms until the condition is moderate or advanced. It can be slowed or prevented, but there is no cure.
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While having a routine eye exam a few months ago, Calvin Blanton got some shocking news -- he had glaucoma.
He was one of 1.3 million new cases expected to be diagnosed over the next decade.
"Probably a person feels if my vision is fine, it must be fine," Blanton said. "There has been no change in my eyesight, yet still I have glaucoma."
There is no cure for glaucoma. But with treatment, any damage can be greatly reduced over time.
Blanton's doctor Paula Newsome, who also has glaucoma, told Channel 9 it starts with too much pressure in the eye.
"What that increase in pressure does is compress the nerve, so you start with a wide open field of vision and it starts compression it," Newsome said.
Many people don't see the eye doctor on a regular basis to get their pressure checked.
In Eyewitness News anchor Scott Wickersham's case, he said he had Lasik vision correction and since his vision was good, he stopped going to the eye doctor.
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For Scott, he said he had a burst blood vessel in the white part of his eye, which is why he went to the doctor, and they discovered the glaucoma.
This is a mistake that many people make.
Over three million Americans have glaucoma, but only have of those people know they have it. Glaucoma is six to eight times more common is African Americans than Caucasians, and it affects people of all ages from newborns to seniors.
Officials said vision is lost from the outside inward, slowly over time. If found early on, doctors can slow or prevent vision loss with medications or surgery.
If you wait until you notice vision loss, it has already done damage and it is typically too late, according to doctors.
Blanton said he is still digesting the news about his glaucoma, but said he would rather know than not.
"You probably take your eyesight for granted, but it can be taken away from you and how would you adapt to that," Blanton said.