Here's my starting 'before' picture with no mascara, eyelashes curled.
Here's what my bare eyelashes look like after using no mascara other than Lancome Hypnose Precious Cells Mascara for just over a month. I don't use mascara on my lower lashes, and I think you can see those haven't changed. I do think that my natural lashes look darker right to the tips now, even without mascara, and my lashline looks a bit thicker. I haven't changed my routine in any other regard, and if anything I've been a bit rougher with my eyelashes - sometimes at night I think they still have mascara on them when they don't and I try to remove it.
I like this mascara a lot; it doesn't make my lashes look clumpy, it lengthens nicely and it's a good true black. I do feel it has improved the condition of my lashes, and I will continue to use it. It's also less expensive than many of the lash conditioning/lengthening treatment formulas that have been launched recently (the Lancome is about £20). It doesn't give as dramatic an effect as the formulas that contain prostaglandins, but then I'd rather avoid the potential side-effects of those. I'd like to see Lancome launch a colourless version for nighttime use too.
I'll continue to monitor the effects, and will report back in another month.