Friday, February 4, 2022

Human eye light phenomenon

Humen Eye :

⇒basically a convex lens

⇒least distance of distinct vision = 25cm

⇒iris : ctrl size of pupil ←focus light

⇒Retina : real & inverted image of obj.

Defects

i) Myopia/short sightedness :

⇒can see near obj but not far

⇒diverging (concave lens)

ii) Hyperopia / hypermetropia/longshightedness :

⇒can see far but not near

⇒Converging (convex lens)

iii) Presbyopia :

⇒elderly person : nearby obj can't seen

⇒Bifocal lens or two separate lens.

iv) Astigmatism:

⇒cylindrical lens.

v) Cataract :

⇒crystalline lens become milky & cloudy at old age

⇒surgery.

Posted by : Jagmohan Singh Panwar

civil topicwise