Narrow-angle glaucoma is much more rare and is very different from open-angle glaucoma in that eye pressure usually goes up very fast. This happens when the drainage canals get blocked or covered over. The iris gets pushed against the lens of the eye, shutting off the drainage angle. Sometimes the lens and the iris stick to each other. This results in pressure increasing suddenly, usually in one eye. There may be a feeling of fullness in the eye along with reddening, swelling and blurred vision.