I just had a random common sense thought… Often times details of a dream can be visually blurry… But if you have poor vision and perscription lenses irl, have you ever noticed in a dream, some circumstances where the scenery is inexplicably sharp and vivid; and used it to reality check?
Yeah I think so the dream looked so vivid and weird I became lucid one night and plus I did not think I should be in a subway tunnel so thats another thing
Ahh! Good one! I should use this as a RC, since I have contact lenses in real life. And I very often dream how I put my contact lenses out of my eyes in a dream and vision doesn’t change at all.
Yeah, I havn’t done this myself, but It’s strange how this is so common sense that I have never realised it before 
but like Mental Enigma shows, it might be so miniscule in scale compared to other common sense dream signs that it could be insignificant