Optics usually refers to things like binoculars, microscopes or anything with lenses. The optical nerve is in the eye. Glasses can be sun glasses, reading glasses and even something to drink out of.

We use glasses for the things we put on our face. Optics can be used to mean how something is perceived by the public in politics. "Oh the optics aren't good." Like a certain picture may appear to suggest something negative. Like if someone claims to be promoting green energy, and then a picture of them playing golf with the CEO of an oil company surfaces." People in the campaign office, at that moment, might say "oh these are bad optics." You might also have heard of "optical illusion(s)" which are instances where visual imagery "tricks" the eye into seeing things a certain way. https://en.wikipedia.org/wiki/Optical_illusion

Thank you very much for your information, Merlyn. I think there are some typos in your text. #1: 'It is plural because THERE are 2 pieces'. #2: 'A spy glass LETS you see something far away' (Without apostrophe). Thanks again for your help.

Eventually you will be able to understand a Latin word when you see it, and understand what it means and when to use it. Often we use the English word in everyday conversations, and the scientific Latin or Greek word for more technical applications. "opt-" is a Latin root that refers to vision, "-ic" is a Latin suffix that is sometimes equivalent to Farsi suffix "-i" . Like with electric, electric means a thing has something to do electrons, optic means something has to with vision. "glasses" is an abbreviation of "eyeglasses", the English word that refers to what the lenses were (and sometimes still are) made of : glass. It is plural because their are 2 pieces. There are other types of "glass": a looking glass (mirror) is a piece of glass that reflects an image, a spy glass let's you see something far away, drinking glasses are for holding a drink, etc. As others have said there are many words derived from "optic", all of which refer to vision or lenses. In a store the Optic Department or an Optical Centre is a place where they make you or you can buy eyeglasses or contact lenses, or possibly have your vision checked by an eye doctor (an optician-"optician" is the technical word for and eye doctor.) But you have to be careful- a place like Gary's Optics could have something to do with any type of lens, so it could sell or make binoculars and scopes, like the other commentator said, and not necessarily eyeglasses. optical illusion: An illusion is something that is not real; an optical illusion is something that fools your eye. In the desert a mirage is an optical illusion.