Well, yes, vinegar can help the black eye. Generally speaking, you should know that apple cider vinegar is quite rich in minerals, vitamins and enzymes. So according to some experts, if you apply vinegar, it will definitely relieve the symptoms because of black eyes. And in common, when blood and other fluids collect in the space around the eye, a black eye can occur. And In some cases, injury can lead to black eyes, and also lead to swelling and dark discoloration around your eyes. For treatments, you can try using ice to reduce the swelling caused by a black eye. In this way, the bruising will start fading in a few days.
Vinegar does have the effect of activating blood circulation. You need to try.However, I think it's not the best choice for you. Aloe can be the best magic stuff for your situation, because it also can activate blood circulation to dissipate blood stasis detumescence and odynolysis. If that stuff won't work, you need to massage your eyes with vinegar or aloe, whatever oil can activate the blood circulation. Now, let me name a few, tea tree oil, walnut oil, olive oil.
Most important, vitamin E need to be added into those oils.
Yes you are right, it is true that vinegar can help black eyes. You can obsolutely have a try. The instruction is that you can put vinegar on a cotton swab then you can rub it on the black eye. The black will go away slowly. What's more, you can try using some cucumbers on your eyes too.