( ( ( Nerve cells ) ( in ( ( the retina ) ( -LRB- ( ( ( rods and ) cones ) -RRB- ) ) ) ) ) ( ( convert ( light ( into ( ( electrical impulses ) ( that ( ( travel ( along ( the ( optic nerve ) ) ) ) ( to ( the brain ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Nerve) (NNS cells)) (PP (IN in) (NP (NP (DT the) (NN retina)) (PRN (-LRB- -LRB-) (NP (NP (NNS rods)) (CC and) (NP (NNS cones))) (-RRB- -RRB-))))) (VP (VBP convert) (ADJP (JJ light) (PP (IN into) (NP (NP (JJ electrical) (NNS impulses)) (SBAR (WHNP (WDT that)) (S (VP (VBP travel) (PP (IN along) (NP (DT the) (JJ optic) (NN nerve))) (PP (TO to) (NP (DT the) (NN brain)))))))))) (. .)))
Nerve cells in the retina (rods and cones) convert light into electrical impulses that travel along the optic nerve to the brain.
(ROOT (S (NP (NP (DT The) (JJ light-sensing) (NNS cells)) (PP (IN in) (NP (DT the) (NN retina)))) (VP (VBP are) (VP (VBN called) (NP (NNS rods) (CC and) (NNS cones)))) (. .)))