Why do some people wear spectacles?

Answer 1

People wear spectacles to correct visual conditions such as hyperopia, myopia and presbyopia. Hyperopia (also known as long sightedness) is a condition where the eye cannot focus on near objects and in some cases the eye won't be able to focus properly on objects at any distance. A positive lens which is convex in shape (+ powered prescription) will be used for this condition. Myopia (also known as short sightedness) is the opposite. A myopic eye won't be able to focus on far away objects but a myopic eye can usually to focus on close up objects with ease. A minus lens which is concave in shape (- powered prescription) will be used to correct this condition. Prebyopia is a condition where the crystalline lens which is inside the eye becomes less flexible with age and loses the ability to focus on near objects. This condition is common for people over the age of 40 years. There are also other more complex reasons for people to wear corrective prescription lenses but these are the main reasons.

Or sometimes you don't need them when ur young but ur eyes change as you get older so u may need them when ur older.