A cataract is the clouding of the lens in the eye. Most cataracts are related to aging (“cataracta senilis”) since the metabolism of the eye lens slows down at advanced age.
The light entering the eye is scattered by protein aggregates, which results in extreme light and glare sensitivity, cloudy vision and the loss of contrast sensitivity. Cataracts are considered to be the principal cause of blindness in the world, although this outcome can be prevented with eye surgery. The centre of the cloudy natural lens is broken up using ultrasound, then removed and replaced with an artificial lens, also known as an intraocular lens.
The use of blue blocking filters is recommended after surgery to reduce exposure from harmful high-energy blue light and to protect the eye.