Cataracts are the most prevalent blinding disease in the world. Surgery is the only option for Cataracts and it is the most frequently performed surgery worldwide. However, how the patient will see after surgery and what type of replacement intraocular lens (IOL) is the best option cannot be known. In this project, computational holography, which can control phase, size and shape of the light beam entering through the eye-pupil, will be utilized to develop a holographic vision simulator for cataract patients. This will be the first cataract simulator for in-vivo testing of multifocal IOLs. We'll develop and perform clinical studies of the novel instrument on patients.