photocell vs electric eye

photocell and electric eye both are nouns.

Word	Noun	Adjective	Verb	Adverb
photocell	Yes	No	No	No
electric eye	Yes	No	No	No

As nouns, photocell and electric eye are synonyms defined as:

photocell and electric eye: a transducer used to detect and measure light and other radiations

Other synonyms of photocell include magic eye, photoconductive cell, photoelectric cell.

photocell (noun)	electric eye (noun)
a transducer used to detect and measure light and other radiations	a transducer used to detect and measure light and other radiations