A cataract is a clouding of the crystalline lens inside the eye, which leads to a decrease in vision. It is the most prevalent, treatable cause of visual impairment and blindness in the world. Cataract surgery with an intraocular lens (IOL) implant is one of the most common and thought to be the most effective surgical procedure in any field of medicine. In this trial, the investigators aimed to evaluate the effect of cataract surgery on circadian rhythm and sleep as well as the effect of the blue light transmission characteristics of the implanted IOL on sleep.