Over the years, rabbits have most often been used in the Draize Eye and Skin tests. Developed in the 1940s, these tests involve holding rabbits in full body restraints so that chemicals can be dripped in their eye or spread on their shaved and scraped skin. The restraint stops the animals from pawing at their eyes or back to relieve the discomfort and so interfere with the experiment. The Draize test is used to measure irritation or corrosion caused to the eye or skin, but it is notoriously unreliable, producing highly variable results. It is also extremely unpleasant and painful, causing eye reddening, swelling, ulceration, even blindness, or skin cracking and bleeding.