Optical illusion and Optical phenomenon

Optical illusion noun - An optical phenomenon that results in a false or deceptive visual impression.

Optical phenomenon and optical illusion are semantically related. In some cases you can use "Optical phenomenon" instead a noun phrase "Optical illusion".

Optical phenomenon noun - A physical phenomenon related to or involving light.

Optical illusion and optical phenomenon are semantically related. Sometimes you can replace phrase "Optical illusion" with "Optical phenomenon", this phrases are similar.