AaM Vision&Visual Acuity 2&3

Question 1

crystalline lens??

Answer 1

responsible for accomodation and it is flexible its shape is not fixed

Question 2

what happens to the crystalline lens as we age??

Answer 2

as we age the flexibility of the lens reduces resulting in reduced power of accommodation and PRESBYOPIA

Question 3

accommodaiton?? and how its acheived

Answer 3

The automatic adjustment in the focal length of the
lens of the eye to permit retinal focus of images of
objects at varying distances

the ability of the eye to change its focus from distant to near objects
(and vice versa). This process is achieved by the lens changing its shape

Question 4

What does the Pelli-Robson chart measure?

Answer 4

contrast sensitivity

Question 5

What is spherical ametropia?

Answer 5

A refractive error where the eye’s optical power causes light to focus either in front (myopia) or behind (hyperopia) the retina, without astigmatism

Question 6

What is emmetropia?

Answer 6

The ideal state of no refractive error; light focuses precisely on the retina.

Question 7

axial ammetropia??

Answer 7

The eye has a standard power (+ 60 D) and there is
an error in axial length

Question 7

How does axial length affect spherical ametropia?

Answer 7

longer axial length (>22.22mm) causes myopia; shorter axial length (<22.22mm) causes hyperopia.

Question 8

How does the refractive power of the cornea and lens influence ametropia?

Answer 8

increased power (too strong >+60D) causes myopia; decreased power (too weak <+60D) causes hyperopia.