electric eye vs photocell

electric eye and photocell both are nouns.

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

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

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

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

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