I must say... these drops are AMAZING. I was feeling very sleepy. My eyes felt drowsy and heavy from studying. These drops wake them up right away! You have got to get these drops, especially if you're a student!
Yes, it did tingle a lot when I put them in. You know that feeling you get when you chew spearmint gum? Imagine your eyes are chewing their own version of freshening gum. That's what it feels like. Yes, it burns, but its not painful. Again, imagine the gum thing. Sometimes when you first bite the gum, the mint feeling is INTENSE and then after a few moments, it dies down. This is the same thing. Its spearmint gum for your eyeballs.
Really wakes you up and keeps your eyes from feeling like crap for a nice while. You can use it UP to 4 times a day.
Ahem... so consider me "on the bandwagon". ;)