Primary open angle Glaucoma (Norwegian elkhound type) is an inherited condition of the eye affecting dogs. Clinical signs of increased eye pressure typically present when dogs are middle-aged but vision deficits may not be noted until older. As the pressure in the eye increases, the eyeball increases in size and is painful. Signs of pain in the eye include excessive blinking, tearing and redness. If left untreated, the increased pressure in the eye leads to optic nerve damage and the gradual loss of vision. Dogs with glaucoma are at risk for lens luxation. Symptoms of lens luxation include excessive blinking, squinting and tearing of the eye. Dislocation of the lens can occur in both the forward and backward position within the eye, but dislocation in the forward position is more common and serious. If not treated immediately, lens dislocation will exasperate the glaucoma and vision loss. Other symptoms may include bulging eyes and cataracts.