As an ophthalmologist, I am very glad that you are conscious of the health of eyes. Wearing sunglasses does help to prevent cataracts.
According to scientific search, cataracts are involved with the UV radiation of sunlight. The sunlight can stimulate crystalline lens aging and result in cataracts. For example, the number of senile cataract patients in Africa and India are higher than that in temperate regions; the incidence of senile cataract in Chinese south regions is obviously higher than that in the north region.
UV-proof sunglasses can effectively prevent the penetration of UV and reduce the damage to eyes.
Mobile phone radiation and the strong light have been related with the pathogenesis of cataract. And the study found that the even low weak microwave radiation, if long time accumulated, will cause the damage to the eyes, which may finally induce cataract and lead to blindness. Thus, wearing the sunglasses is really useful and necessary for the people with cataract.
In fact, wearing sunglasses would not prevent cataracts. Maybe sunglasses could limit UV exposure from sunglight to reduce the risk of developing some types of cataracts. Because cataracts are a common eye disorder that mainly caused by aging. While cataracts could affect people of any age, they are most common in elder adults. In fact, two-thirds of all adults over age 60 have some sign of cataract formation. It is a good idea to err on the side of caution and wear sunglasses to slow down the procedure of developing cataracts.