As pretty much anyone who has ever had a breakout knows, pimples are fleeting — but an acne scar, much like a diamond, lasts forever (or at least, it feels like it does). In this instance, when we say "scar," we're talking about those red or brown marks that linger on your face well after that zit has been beaten into submission. Also called post-inflammatory hyperpigmentation, these spots aren't permanent like actual scars, but they can hang out on the skin for weeks or even months post-breakout. And they can be frustratingly resistant to most dark-mark faders and redness reducers. Best of all, they aren't selective about whom they attack — all skin tones, from the palest of the pale to the darkest of the dark, can be affected.I fall pretty distinctly into that "palest of the pale" category, so my hyperpigmentation is of the Flaming-Hot-Cheeto variety. While the spots don't have the raised texture and sensitivity that actual blemishes do, they are still a bitch to cover up — and, despite my access to the best makeup and pro concealer tips in the world, they still continue to mock my feeble attempts to hide them.Which is why I've shifted my focus from makeup to skin care. Rather than try to cover angry red spots, I've been working overtime with brightening and dark-spot-diminishing treatments. I'd found some moderate relief with a few products (like this baller Talika sheet mask ), but they were mostly meant for special treatments, not everyday remedies. And then I found Peter Thomas Roth's Camu Camu Power C x 30 Vitamin C Brightening Sleeping Mask. Curse the marketer who came up with that mouthful of a name.I'm no stranger to sleeping masks; Laneige and May Coop are two that I use routinely, and Aurelia 's probiotic one is a new favorite. But the PTR wasn't on my radar. I had heard the spiel about its star ingredient, camu camu (a super-charged, vitamin-C-rich berry that is said to be the new açai), but since I wasn't a regular consumer of the brand, this honestly wasn't a product on my must-try list.Big mistake. Huge. I don't really buy into the whole "overnight miracle" concept (with a few notable exceptions), but this is the real deal. My skin was in the throes of a just-finished breakout on one side of my face and a month-old patchwork of spots on the other. But after one night — and I legit mean one night — with this mask, those marks were significantly less noticeable. Like, half the redness they were previously. I've been religiously slathering the mask on my face and neck ever since.The first week was relatively similar, with me waking up each morning to spots that were nearly half as intense as they had been the night before. Week two has been a bit of a plateau, with results that aren't quite so pronounced — but I'm still seeing an improvement each morning. Are the marks gone? I wish. But they are a lot easier to cover up with concealer, and they don't make me look like my face was recently attacked by an inept zombie.A few things to note: First, this mask is sticky. Like, really sticky. It absorbs into the skin, but leaves behind a bit of an orange cast and a mild, Scotch Tape kind of adhesive feel when you touch it. I made the mistake of putting it on and directly jumping into bed, and I was rewarded with orange-tinted silk pillowcases and a tacky pull every time I lifted my face up. So, give it ample time to sink in before hitting the sheets — and maybe don't use it with your light-colored linens.Second, there is a bit of a stinging sensation when you apply it. Mind you, I was using a pretty intense anti-acne regimen that included glycolic and salicylic pads and a retinol cream, so that probably intensified the sting, but this mask nonetheless gave me a bit of a painful tingle. It went away after the first five minutes or so, but I was still worried I would wake up the next a.m. with flaky, irritated skin. Thankfully, that didn't happen. That said, I would start off using this twice a week, and then see how your skin reacts before you go whole-hog on it.Third, this does bupkis on active blemishes. It won't exacerbate them, but don't expect it to affect the lifespan of the zit or prevent breakouts — this is purely for pigmentation problems.All of that aside, as far as brightening products go, this is my new holy grail. Between the red-mark eradication and the clarity and evening-out of my skin tone, I've finally found an answer to kick those scars to the curb. This may not totally erase them, but it comes pretty damn close.Camu Camu Power C x 3 Vitamin C Brightening Sleeping Mask, $62, available at Peter Thomas Roth