How to put in/on contact lenses? "On" or "In" here? Is "on"/"in" really needed? Which is right?

You put **in** contact lenses.

Generally, you put glasses “on” and contact lenses “in”

You definitely can’t just “put contact lenses” without adding an “in” (assuming you are wearing them) or *maybe* an “on” (if you are not wearing them, e.g. “I put my contacts *on* the counter after taking them out) or some other preposition. You need to say or imply *where* they are.

Either. I’d use “in”. You put glasses on, you put clothes on. But we put contact lenses inside our eyelids. It’s more penetrative, inside the body, like a tampon or a catheter. But you can still use “on”, since the thing ends up on the surface of your eye.

Put *in* contact lenses. "On" sounds wrong to me. "Put contact lenses" without on or in is absolutely wrong.

Put in contacts. Put on glasses.

Put "on" is incorrect. You put *on* glasses. They go onto your face. You put *in* contact lenses. They go into your eyes (as in, behind your eyelid). Since you technically put a contact lens onto your eye*ball*, this seems like a situation where "on" would still work, but I have never heard any native speaker say "put on contacts" in my life. It's comprehensible and logical, but language-wise it's incorrect.

Well, I put on my lenses. I guess either on or in is OK.

Either one sounds fine.

I’ve heard people say “let me put on my contacts real quick”. In this case “contact lenses” are being shortened to just “contacts” for convenience. I’ve heard both in and on, and neither would cause any confusion to a native speaker but I suppose “in” is more natural.

Southeast US here. I've always heard and said "in."

"put on" = begin to wear "put in" is used because you place them in your eyes/behind the eyelids. Both are correct, but convey slightly different connotations imo. "put in" is definitely more common.

As a native speaker, both sound fine to me. This is speaking as someone from Texas.

You put contact lenses both in your eyes and both on your eyes. Glasses can only be put on your face.

Generally, you put contact lenses *in,* because they are inside of your eyelid. But it would make perfect sense to "go put *on* some contacts," because they do technically count as clothes. Sounds fine to me.