( They ( ( say ( no-one ( ( should ever ) ( ( ( ( ( ( ( look directly ) ( at ( the Sun ) ) ) ( under ( any circumstances ) ) ) , ) ( ( ( with or ) without ) ( optical aids ) ) ) , ) ( as ( this ( can ( cause blindness ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP say) (SBAR (S (NP (NN no-one)) (VP (MD should) (ADVP (RB ever)) (VP (VB look) (ADVP (RB directly)) (PP (IN at) (NP (DT the) (NNP Sun))) (PP (IN under) (NP (DT any) (NNS circumstances))) (, ,) (PP (IN with) (CC or) (IN without) (NP (JJ optical) (NNS aids))) (, ,) (SBAR (IN as) (S (NP (DT this)) (VP (MD can) (VP (VB cause) (NP (NN blindness))))))))))) (. .)))
They say no-one should ever look directly at the Sun under any circumstances, with or without optical aids, as this can cause blindness.
(ROOT (S (S (VP (VBG Looking) (ADVP (RB directly)) (PP (IN at) (NP (DT the) (NN sun))))) (VP (MD can) (VP (VB cause) (NP (NN blindness)))) (. .)))