Zeiss brand IOLMaster, Version 1-5, Biomicroscope, Slit-Lamp, AC-Powered, || Product is manufactured by Carl Zeiss Meditec AG (Jena), || Carl Zeiss Promenade 10, Jena, Germany 07745; and distributed by Carl Zeiss Meditec, Inc., Dublin, CA || This device is intended for use primarily by physicians and health care workers and may be only used under the supervision of a physician. This device will not be sold to the general public. The IOLMaster is intended for the biometric determination of ocular measurements of axial length, anterior chamber depth, corneal radius, white-to white (WTW), and for the measurement of pupil size and deviation of the visual axis from the center of the pupil. For patients who are candidates for intraocular lens (IOL) implantation, the device also performs calculations to assist physicians in determining the appropriate IOL power and type for implantation