( Light ( ( ( ( ( enters ( through ( ( the opening ) ( of ( ( the pupil ) ( -LRB- ( ( ( the ( dark spot ) ) ( in ( ( the middle ) ( of ( your eye ) ) ) ) ) -RRB- ) ) ) ) ) ) ) , ) and ) ( is ( focused ( by ( the lens ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Light)) (VP (VP (VBZ enters) (PP (IN through) (NP (NP (DT the) (NN opening)) (PP (IN of) (NP (NP (DT the) (NN pupil)) (PRN (-LRB- -LRB-) (NP (NP (DT the) (JJ dark) (NN spot)) (PP (IN in) (NP (NP (DT the) (NN middle)) (PP (IN of) (NP (PRP$ your) (NN eye)))))) (-RRB- -RRB-))))))) (, ,) (CC and) (VP (VBZ is) (VP (VBN focused) (PP (IN by) (NP (DT the) (NN lens)))))) (. .)))
Light enters through the opening of the pupil (the dark spot in the middle of your eye), and is focused by the lens.
(ROOT (S (NP (DT The) (NN pupil)) (VP (VBZ is) (NP (NP (DT the) (NN name)) (PP (IN of) (NP (NP (DT the) (JJ black) (NN opening)) (PP (IN in) (NP (NP (DT the) (NN eye)) (SBAR (WHNP (WDT that)) (S (VP (VBZ lets) (SBAR (S (NP (NN light)) (VP (VBP enter))))))))))))) (. .)))