Researchers at the University of Iowa are trying to prod anyone over the age of 40 to get their eyes examined at least every other year. One of the leading causes of blindness can be stopped if it’s caught early, according to University of Iowa opthalmology professor Wallace Alward. Two-to-three-million Americans have glaucoma and many don’t know it because it comes on so slowly. Professor Alward is director of the U-of-I Glaucoma Service. He says there are four basic risk factors for glaucoma, the foremost being people age 40 and over. This is Glaucoma Awareness Month. Alward says Iowans need to heed the warnings and protect their vision.Having an eye-pressure check at a shopping mall come up negative does not mean a person is safe from the disease. He says only in a full eye exam can glaucoma be accurately detected.