( ( Be ( able ( to ( choose ( correct ( lens type ) ) ) ) ) ) . )
(ROOT (S (VP (VB Be) (ADJP (JJ able) (S (VP (TO to) (VP (VB choose) (NP (JJ correct) (NN lens) (NN type))))))) (. .)))
Be able to choose correct lens type.
(ROOT (S (NP (JJ Concave) (NNS lenses)) (VP (MD can) (VP (VB correct) (NP (NN myopia)))) (. .)))