It's a two phase solution so you shake it up first to mix the oil and the water and then apply it to a cotton wool pad and then place it on your eyelid and let it do the rest of the work. I found that you have to shake it really vigorously to get the solution to mix and stay mixed for a decent amount of time, or else it just separates really quickly.
I tend to leave it to soak on my eyelid for about 5 seconds and then gently go from the inner to outer corner of my eye. Depending on how much makeup I have on, it can take anywhere from about 2-10 swipes to remove it all but it does remove it ALL. I've tried it on a variety of products like normal/waterproof mascara (Benefit's They're Real! - notoriously difficult to remove but this manages it), gel liner, liquid liner, cream and powder eyeshadow. You do need to work at it a bit more for the gel liner and waterproof mascara but it doesn't leave my eyes stinging afterwards even if I've been a bit over enthusiastic/rushing to get it off.
It does leave a slightly oily residue around my eyes but as I tend to remove my eye makeup first and then the rest of my makeup, my L'Oreal Micellar Solution picks up the oil and my skins left squeaky clean and oil free.
Overall, I'm pleased I picked it up and it's definitely my new go-to for stubborn eye makeup. It's a total bargain at £2 and even at it's normal price of £3.49, I'll definitely be picking up another when it's runs empty.