It is also used to improve the accuracy of intraocular lens calculations before cataract surgery (particularly when there has been previous refractive surgery) and to investigate unexplained visual symptoms. Topography is also indicated for evaluation and treatment of Keratoconus, or for consideration of refractive surgery, can expect to have this test at their initial consultation. In some patients, Topography may need to be repeated at intervals of 3-12 months. This test provides invaluable information about your cornea and allows us to better care for your eyes. It is important we test both eyes initially, even if we are only aware of a problem with one eye. The procedure is completely painless.