In fact, convex lenses used to correct farsightedness came along nearly 300 years before the concave lenses to correct nearsightedness did.
Farsightedness and nearsightedness are two common eyesight deficiencies.
Farsightedness means the individual has problems seeing close-up and nearsightedness occurs when the individual has problems seeing far away.
The use of concave lenses (lenses that depress inward) to correct nearsightedness is attributed to Nicholas of Cusa and the thought that specific lenses were required to ease various problems with vision prevailed for centuries.
Roughly 145 million of those people could have normal vision with the help of eyeglasses and are simply suffering from problems like nearsightedness, farsightedness, and astigmatism, and many are in low-income countries.
