( Myopia ( ( can ( be ( corrected ( by ( ( using ( a ( concave lens ) ) ) ( to ( ( ( diverge , ) or ) ( ( ( spread out ) , ) ( ( ( the light ) so ) ( that ( ( when ( it ( passes ( through ( the ( lens system ) ) ) ) ) ) ( , ( it ( comes ( to ( focus ( on ( the retina ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Myopia)) (VP (MD can) (VP (VB be) (VP (VBN corrected) (PP (IN by) (S (VP (VBG using) (NP (DT a) (JJ concave) (NN lens)) (S (VP (TO to) (VP (VP (VB diverge)) (, ,) (CC or) (VP (VB spread) (PRT (RP out)) (, ,) (SBAR (ADVP (NP (DT the) (NN light)) (RB so)) (IN that) (S (SBAR (WHADVP (WRB when)) (S (NP (PRP it)) (VP (VBZ passes) (PP (IN through) (NP (DT the) (NN lens) (NN system)))))) (, ,) (NP (PRP it)) (VP (VBZ comes) (S (VP (TO to) (VP (VB focus) (PP (IN on) (NP (DT the) (NN retina))))))))))))))))))) (. .)))
Myopia can be corrected by using a concave lens to diverge, or spread out, the light so that when it passes through the lens system, it comes to focus on the retina.
(ROOT (S (NP (JJ Concave) (NNS lenses)) (VP (MD can) (VP (VB correct) (NP (NN myopia)))) (. .)))