This is the first time I'm using contact lenses. I have a 60-ml bottle Complete Multi-Purpose Solution for cleaning and storing my contact lenses. I find out that I've been consuming it pretty fast and now after only 2 days I feel like I've used up half the bottle (can't see through the bottle so I don't know how much is left, but not so much...)! Did I use too much solution? How much would be enough and how long should a 60-ml bottle last? Thank you!