Application: Tetracaine is a topical opththalmic anesthetic used to relieve the pain the skin and as an eye drops for minor eye operations. It prevents voltage-sensitive release of Ca2+ from sarcoplasmic reticulum and can be used as a spinal anesthetic. Tetracaine is a local anesthetic (numbing medicine). It works by blocking nerve signals in your body. Tetracaine topical (for the skin) is used to numb different parts of the body before a medical test or procedure. Tetracaine topical may also be used for purposes not listed in this medication guide.