Electric eye and Sensing element

Electric eye noun - A transducer used to detect and measure light and other radiations.

Sensing element and electric eye are semantically related. In some cases you can use "Sensing element" instead a noun phrase "Electric eye".

Sensing element noun - Any device that receives a signal or stimulus (as heat or pressure or light or motion etc.) and responds to it in a distinctive manner.

Electric eye and sensing element are semantically related. Sometimes you can replace phrase "Electric eye" with "Sensing element", this phrases are similar.