Glaser received her BFA at the Kansas City Art Institute, and her MFA at Indiana University in Bloomington, in 1983. After graduate school, she worked as a printer, but that soon changed when she came by an underwater Instamatic camera. She learned to scuba dive, and with her underwater camera she began photographing the springs of North and Central Florida with available light alone.
She captured photographs of manatees and other wildlife before shifting focus to the underwater landscapes. She saw the underwater scenes as not only habitats for wildlife, but also as landscapes able to stand on their own as meaningful artworks. Glaser later continued her photography at the Big Cypress National Preserve and Everglades National Park. In 2014, her work was part of an exhibition on display at the Harn Museum of Art in Gainesville, Florida titled "The Mark of Water: Florida's Springs and Swamps by Karen Glaser." Speaking of her work, Glaser stated “I didn't learn how to photograph under water. If I did, I would have used a flash. I would have tried to avoid the matter in the water. But for me, that stuff is the lifeblood of the image. I was trained in a fine art program. I just picked up my camera and started photographing like I do above water.” Her work is inspired by the wondrous ecological diversity that Florida has to offer.