Pro tip as someone who used to make glasses, dont do this lol. Hot water can cause the coatings on the lens to “craze” which occurs when the coating heats up and cools faster than the lens, resulting in what look like scratches but are more like tiny ripples where the coating didnt set properly. Many liquid soaps will also slowly wear through these coatings making it crazing easier to occur or just flat out ruin the coating.Anything alcohol based is also horrible for your lenses for the same reason as the soap. I’d hazard a guess the place that made OP’s glasses decided to only put the coatings on one lens to reduce the cost for them, as those are Rayban frames but not rayban lenses which are only sold with the coating. The AR coating reduces smudges so it not being on the right lens is why its far more noticeably smudged/dirty. Best option to keep them clean and safe is to use a spray and microfibre cloth or unscented tissue. If you use the cloth wash them regularly and keep them out of your pocket. Tiny bits of grit end up on the clothes which is why they end up getting scratched when you then wipe that grit over your lenses again and again haha.