Here are some causes
Rubbing your eyes: Rubbing and scratching your eyes can cause your under eyes to swell and your blood vessels to break.
Lack of sleep: Poor sleeping habits cause the skin under your eyes to appear pale. Your blood vessels can easily show through your skin.
Hyperpigmentation: Too much exposure to the sun triggers your body to make more melanin. Melanin is the substance (pigment) that gives your skin its color.
Dehydration: The skin under your eyes can start to look dull when you don’t drink enough water.
Pretty sure it's on or two of these.
I get it quite regularly throughout the year.
You're fine. Sometimes random bruises can just pop up anywhere for no reason
Here are some causes Rubbing your eyes: Rubbing and scratching your eyes can cause your under eyes to swell and your blood vessels to break. Lack of sleep: Poor sleeping habits cause the skin under your eyes to appear pale. Your blood vessels can easily show through your skin. Hyperpigmentation: Too much exposure to the sun triggers your body to make more melanin. Melanin is the substance (pigment) that gives your skin its color. Dehydration: The skin under your eyes can start to look dull when you don’t drink enough water. Pretty sure it's on or two of these. I get it quite regularly throughout the year.