Biology Is Love

ACCOMMODATION REFLEX -Souti Das   The process by which the curvature of the lens is increased is called accommodation. It is sometimes referred as near response too, i.e, adjustment of visual apparatus from distant vision to near vision. For this adjustment three changes occur: (i) Constriction of pupils (ii) Increased curvature of the anterior surface of the lens (iii) Convergence of the eyeballs. PATHWAY- Retina ↓ Occipital cortex (area 17) ↓ Association fibres ↓ Frontal eye field (area 8) ↓ Internal capsule ↓ Midbrain ↓ 3rd nerve nucleus of both side (i) Extraocular muscle (medial rectus)      (ii) Parasympathetic pathway ↓ Eye (Pupils + Ciliary body) MECHANISM OF ACCOMMODATION REFLEX- During accommodation, initially, the image is formed behind the retina, which is then focussed sharply on the retina through the following changes- (i) Pupillary constriction occurs due to parasympathetic activity from the Edinger- Westphal nucleus (a part of the 3rd nerve nucleus). (ii) Anterio