Question

Which part of the eye acts as a secondary area of refraction to "fine tune" the focus? the iris the cornea the lens the retina

Answer 1

The lens

Step-by-step explanation:

Lens of human eye have ability to change its shape and thereby changing the focus for near or far vision. The ability of lens to fine tune the focus by change in its shape is called as accommodation and is done with help of ciliary muscles. Contraction of ciliary muscles makes the lens more round to focus the closely located objects. Relaxed ciliary muscles makes the lens to assume flat or ovoid shape to focus on distantly placed objects.

Answer 2

The part of the eye that acts as a secondary area of refraction to fine tune the focus is the lens. The lens of the eye is a biconvex, transparent structure of the eye that helps in refraction along with the cornea. Most of the refracting of the light rays happens in the cornea, but the lens help refract light to be focused on the retina by changing its shape to focus on objects at various distances.