( ( Your eye ) ( ( has ( ( a ( variable opening ) ) ( called ( the pupil ) ) ) ) ; ) )
(ROOT (S (NP (PRP$ Your) (NN eye)) (VP (VBZ has) (NP (NP (DT a) (JJ variable) (NN opening)) (VP (VBN called) (NP (DT the) (NN pupil))))) (: ;)))
Your eye has a variable opening called the pupil ;
(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)))) (. .)))