( ( The pupil ) ( ( is ( ( a hole ) ( in ( ( the iris ) ( that ( ( allows light ) ( into ( the eye ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN pupil)) (VP (VBZ is) (NP (NP (DT a) (NN hole)) (PP (IN in) (NP (NP (DT the) (NNS iris)) (SBAR (WHNP (WDT that)) (S (VP (VBZ allows) (NP (NN light)) (PP (IN into) (NP (DT the) (NN eye)))))))))) (. .)))
The pupil is a hole in the iris that allows light into the eye.
(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.