The 10-second pinch test that'll tell you exactly how to treat your dark circles and bags.

Chat to any woman at 8:21am on a Monday morning and there’s a good chance she’ll bring up her dark circles and under eyes.

Under eye bags, eye bags, dark circles… whatever you call yours, they’re not very nice. They’re also stubborn and don’t always cheer up after a good night’s sleep like they should.

But did you know dark circles and under eye bags are not the same thing? That they’re two very different conditions?

We didn’t either until we saw this helpful video from Sali Hughes Beauty.

In a Q&A about all things skin, the British beauty journalist sat New York dermatologist Dr Dennis Gross down on a couch and got him to answer her followers’ skincare questions.

The 36-minute interview covers everything from bacne and dermarolling to wrinkles and exfoliation. But possibly the biggest (and most practical) advice came up in response to a question about how to get rid of dark circles and under eye bags.

“The truth of the matter is, there’s two basic categories[talking about dark circles and bags] – one is actual pigmentation in the skin, the other is skin that’s thin and shows the dark veins and fat pads underneath… they’re two problems,” Dr Gross tells Hughes.

You can listen to Dr Dennis Gross’ dark circle and under eye bag advice in the Sali Hughes beauty video below. Post continues after video.

So, how do you know if you’ve got dark circles OR under eye bags? According to Dr Gross, the easiest way is to try a little something called ‘the pinch test’.

“What you want to do is take your skin [under the eye] and gently lift it up. When you lift it up, look at what happens to the colour of the skin at the dark circle,” he says.

“If when you lift it up, off the skin’s structures… the pigmentation does not change and it stays brown, it’s telling you that pigmentation is the primary problem. If when you lift it up, it all of sudden comes back to a normal colour, you know it’s because the skin is too thin and more transparent.”

Your result, Dr Gross says, is “the great divide” between dark circles and under eye bags.

The good news is, these two skin issues can be treated or improved in two different ways.

Best products for dark circles

So, you pinched the skin under your eye and the colour didn’t go away? That means pigmentation is your primary problem, according to Dr Gross.

Put simply, dark circles are caused by an increase in melanin (colour or pigment) around your sensitive eye area.

Dr Gross recommends “if you have pigmentation, you have to look to bleach it and bring down the melanin with retinols and/or vitamin C.”

Associate Professor and Dermatologist Michael Freeman also suggests looking for products containing licorice root extract.

“There is some evidence this inhibits the melanin factory in the cells without causing toxicity to the cells,” he wrote for The Conversation.

To fight pigmentation, try these guys on.

The Ordinary Advanced Retinoid 2%, $17.90

Palmer's Cocoa Butter Formula White & Even Tone Correcting Face Oil, two for $12.98

ECO. Vitamin C Face Serum, $19.99

Re Retinol Intense Repair & Regen Boost, two for $24.98

Re Pure Vitamin C Serum Collagen Booster, two for $24.98

Best products for under eye bags

You can tell you belong in the under eye bags camp, Dr Gross says, if the colour under your eyes went away when you pinched the skin. Your problem is less to do with pigment, and everything to do with thinning of the skin under your eyes.

Think of thin skin under your eyes like a slightly frosted glass window. All the bits you don't want to see, like blood vessels and fat pads, are semi-visible, hence the appearance of dark circles.

This becomes more prominent as we age and our skin loses collagen and elastin (the stuff that makes your skin plump and bouncy).

"If you have a loss of firmness and the transparency is there because of thinning [skin under your eyes], think collegen building," Dr Gross advises.

"You can never go wrong with vitamin C, but to plump the skin [you need] hyaluronic acid. It plumps the skin to lift if off the structures beneath."

Thankfully, vitamin C and hyaluronic acid are in lots of products on the market. Here are a few we're keen on.

Mario Badescu Hyaluronic Eye Cream, $26

NIP+FAB Dragon's Blood Fix Plumping Mask, $22.99

Estee Lauder Advanced Night Repair Synchronized Recovery Complex II, $100

Re Hyaluronic Acid Serum Hydration Booster, two for $24.98

L'Oreal Revitalift Filler Renew Hyaluronic Replumping Serum, $19.99

You can watch Sali Hughes' full interview with Dr Dennis Gross below.

Have you tried the pinch test? Do you have dark circles or under eye bags?