( ( ( ( ( Light ( ( enters ( the eye ) ) ( through ( the pupil ) ) ) ) , ) and ) ( ( the lens ) ( focuses ( ( the light ) ( on ( the retina ) ) ) ) ) ) . )
(ROOT (S (S (NP (NNP Light)) (VP (VBZ enters) (NP (DT the) (NN eye)) (PP (IN through) (NP (DT the) (NN pupil))))) (, ,) (CC and) (S (NP (DT the) (NN lens)) (VP (VBZ focuses) (NP (NP (DT the) (NN light)) (PP (IN on) (NP (DT the) (NN retina)))))) (. .)))
Light enters the eye through the pupil, and the lens focuses the light on the retina.
(ROOT (S (NP (NP (DT The) (NN pupil)) (PP (IN of) (NP (DT the) (NN eye)))) (VP (VBZ allows) (ADJP (JJ light) (S (VP (TO to) (VP (VB enter)))))) (. .)))
The pupil of the eye allows light to enter.