( ( ( The eye-lid ) ( is ( half open ) ) ) ( , ( ( ( ( the ( eye stares ) ) and ) ( the pupil ) ) ( ( becomes bigger ) . ) ) ) )
(ROOT (S (S (NP (DT The) (NN eye-lid)) (VP (VBZ is) (ADJP (RB half) (JJ open)))) (, ,) (NP (NP (DT the) (NN eye) (NNS stares)) (CC and) (NP (DT the) (NN pupil))) (VP (VBZ becomes) (ADJP (JJR bigger))) (. .)))
The eye-lid is half open, the eye stares and the pupil becomes bigger.
(ROOT (S (NP (NP (DT The) (NN opening)) (PP (IN in) (NP (NP (DT the) (NN front)) (PP (IN of) (NP (DT the) (NN eye)))))) (VP (VBZ is) (VP (VBN called) (NP (NN pupil)))) (. .)))