Figure 4. Age-related losses or gains in circadian photoreception relative to a 10-year-old eye for phakic eyes, for 20 and 30D blue-blocking (AcrySof SN60AT, Alcon Laboratories, Fort Worth, TX) and for UV-only blocking intraocular lenses (IOLs) regardless of dioptric power (ClariFlex, Advanced Medical Optics, Santa Ana, CA). Cataract extraction with IOL implantation produces significant gains over phakic eyes, particularly with UV-only blocking IOLs that do not filter out shorter wavelengths vital for non-visual photoreception.