There are no comprehensive studies of how many injuries costume contact lenses cause. Costume, cosplay or theatrical contact lenses also might let less oxygen through to the eye, because the paints and pigments used to add color make the lenses thicker and less breathable. The advantages of cosplay is numerous. People have been blinded by costume contact lenses. Improperly sized lenses can cause corneal abrasions, corneal ulcers and potentially blinding painful bacterial infections like keratitis.