Tanu sree's grand mother uses a biofocal lens.can you write a short note on eye defect of her grandmother
Answers
Answer:
Bifocal eyeglass lenses contain two lens powers to help you see objects at all distances after you lose the ability to naturally change the focus of your eyes due to age, also known as presbyopia. Due to this specific function, bifocal lenses are most commonly prescribed to people over the age of 40 to help compensate for the natural degradation of vision due to the aging process.
Regardless of the reason you need a prescription for near-vision correction, bifocals all work in the same way. A small portion in the lower part of the lens contains the power required to correct your near vision. The rest of the lens usually is for your distance vision. The lens segment devoted to near-vision correction can be one of several shapes:
Answer:
Bifocal lenses are used in spectacles of a person suffering from Presbyopia .
Short note on presbyopia :-
Presbyopia is the gradual loss that the eyes are unable to see the nearby objects clearly . It is mainly seen in ageing people . People in there mid-40s might notice this eye defect . Presbyopia is caused by a hardening of the lens of your eye, which occurs with aging . As your lens becomes less flexible, it can no longer change shape to focus on close-up images. As a result, these images appear out of focus . It can be cured by using bifocal len .