( Thus ( ( , ( ( ( light rays ) ( enter ( the eye ) ) ) , ) ) ( ( ( ( ( ( get ( partially bent ) ) , ) ( continue ( through ( ( the pupil ) ( -LRB- ( ( which ( is ( a ( black hole ) ) ) ) -RRB- ) ) ) ) ) ) and ) ( then ( enter ( ( the lens ) ( of ( the eye ) ) ) ) ) ) . ) ) )
(ROOT (S (RB Thus) (PRN (, ,) (S (NP (JJ light) (NNS rays)) (VP (VBP enter) (NP (DT the) (NN eye)))) (, ,)) (VP (VP (VB get) (ADJP (RB partially) (JJ bent))) (, ,) (VP (VB continue) (PP (IN through) (NP (NP (DT the) (NN pupil)) (PRN (-LRB- -LRB-) (SBAR (WHNP (WDT which)) (S (VP (VBZ is) (NP (DT a) (JJ black) (NN hole))))) (-RRB- -RRB-))))) (CC and) (VP (ADVP (RB then)) (VB enter) (NP (NP (DT the) (NN lens)) (PP (IN of) (NP (DT the) (NN eye)))))) (. .)))
Thus, light rays enter the eye, get partially bent, continue through the pupil (which is a black hole) and then enter the lens of the eye.
(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))))))))))))) (. .)))