Thursday, June 21, 2018

presbygopi -

Presbygopi  or the old eye is caused by the lens of the eyepiece accommodation is not working properly consequently the eyepiece can not focus the light to the yellow point properly, so the eyes can not see the far or near. Accommodation power is the ability of the eyepiece to bulge and flatten. The presbyter can be overcome with a double lens containing plus (+) and minus (-) lenses.