( ( ( The ( more negative ) ) ( ( the value ) ( of ( ( ( the ( correcting lens ) ) , ) ( the greater ) ) ) ) ) ( the ( myopia . ) ) )
(ROOT (FRAG (X (X (DT The) (ADJP (RBR more) (JJ negative))) (NP (NP (DT the) (NN value)) (PP (IN of) (NP (NP (DT the) (JJ correcting) (NN lens)) (, ,) (NP (DT the) (JJR greater)))))) (NP (DT the) (NN myopia) (. .))))
The more negative the value of the correcting lens, the greater the myopia.
(ROOT (S (NP (JJ Concave) (NNS lenses)) (VP (MD can) (VP (VB correct) (NP (NN myopia)))) (. .)))