( ( ( ( ( Lens C ) , ) ( on ( the right ) ) ) , ) ( ( is ( a ( double ( concave lens ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Lens) (NNP C)) (, ,) (PP (IN on) (NP (DT the) (NN right))) (, ,)) (VP (VBZ is) (NP (DT a) (JJ double) (NN concave) (NN lens))) (. .)))
Lens C, on the right, is a double concave lens.
(ROOT (S (NP (JJ Concave) (NNS lenses)) (VP (MD can) (VP (VB correct) (NP (NN myopia)))) (. .)))