Biometry test: This special test measures the eye's shape and size. It is unprofessional for a surgeon to carry out cataract surgery on patients without running this test on them. A biometric test is a unique tool to measure or calculate the power of intraocular lens implants for cataract surgery. Dear reader, we want you to know that the moment you hear your doctor telling you that he needs to run a biometric test on you, you should rest assured you're in the right place.