Vaseline or under eye cream for dark circles
Vaseline is a commercial name for white petroleum jelly which is essentially a combination of mineral oils, paraffin, and microcrystalline waxes that mix together to create a thick jelly whose melting point is slightly above the human body. It is called an occlusive product/ingredient. Occlusive ingredients hydrate the skin and form a layer on top of your existing skin layers/barrier. However, they can be a deterrent in the human natural exfoliation process leading to medical conditions such as milia (tiny white cysts which are whitish or yellowish in color). This is best avoided.
Vaseline etc is essentially meant for dry or damaged skin and to apply on minor cuts & scrapes. It is advised in its own labeling that "When using this product avoid contact with eyes". This means that the product should not be used anywhere near the eye region, so the warning is given by the makers themselves on their labels. Therefore for those who feel that vaseline is a good alternative to under eye cream for dark circles, it is not by any long shot. It is essentially a thick moisturizer and does not have any property to fight the menace of under-eye dark circles. It is like comparing apples and oranges, each has its own properties and one cannot be used in place of another.
If vaseline or moisturizers could do the trick, there would be no under eye creams in the market. No one would need to make one begin with if it was so simple. Manufacturers of under-eye creams make them with special ingredients (natural or artificially created) whose sole function is to minimize or reduce the impact of these dark circles, leading to fading away over a period of time. It is best and safest to use an under eye cream made under the directions of dermatologists and / or ophthalmologists (specialized eye physicians).
Recommended Read: Vaseline on your face
In the end, if you wish to use a good under eye product, don't go for Vaseline or such moisturizers in the market. For this delicate part of the face, use a specially formulated cream like Eyecojic, which is made with naturally derived products and is made by OLS, a pioneer in optho products since 1973. Under-eye cream on Amazon is available in easy to carry tube and fits in easily into a purse. Buy one today.