know before using face cream.

Eye and face cream formulas can be pretty similar. Of course, this varies from brand to brand, but it’s certainly possible for a company to formulate and test a product that works perfectly well on your face and under your eyes. So while in principle there’s nothing with using face cream around your eyes, there are few issues you should be aware of:Face creams are designed for the skin on your face, not the very thin skin under your eyes. So, they might be too greasy. That doesn’t mean they won’t work it just means they might not feel as nice.
Eye creams (at least ones from reputable companies) should be tested to see if they are harmful if you accidentally get some in your eye. Face creams may or may not be tested this way. Look at the Olay products and you’ll see that the eye cream is ophthalmologist tested and the face cream is not.

Face creams may contain fragrance or other ingredients that can be irritating when used close to your eyes. The Olay Regenerist is a good example because the face cream has fragrance while the eye cream does not.
Depending on which brands you buy, you can use your facial moisturizer as an under eye cream. But you might be better off finding an inexpensive eye cream from a brand you trust.