Final answer:
In the United States, cataract surgery—where a cataract-clouded lens is replaced with an intraocular lens—is a common and usually successful procedure to regain distant vision, although some patients may still require reading glasses for presbyopia. The power of the intraocular lens is determined by whether the patient was originally nearsighted or farsighted. Preventative measures for cataracts include protection against UV-B rays with plastic sunglasses.
Step-by-step explanation:
Every year in the United States, it is common for individuals to undergo cataract surgery to replace the clouded lens of the eye with an internal, intraocular lens. This procedure's primary aim is to restore perfect distant vision, and for many patients with cataracts, it has proven to be an easy and successful treatment. A large majority of cataract surgeries are successful; however, the exact number of surgeries and their success rates can vary from year to year. When the cataract-clouded lens is replaced with an intraocular lens, the power to correct vision depends on whether the person was nearsighted or farsighted before the surgery. If the individual was nearsighted, the power of the intraocular lens implanted would typically be less than that of the removed lens to account for the original short-sightedness. Presbyopia, or the loss of the eye's ability to change focus for seeing objects at varying distances, may still require individuals to use reading glasses after surgery.
Cataract development is associated with age and repeated exposure to UV-B rays, with a high prevalence among those aged 65 to 74. It's also worth noting that using sunglasses that block UV rays, particularly those made from plastic, provides effective prevention against cataract formation.