Thanks for writing here.
Brown spots and black circles around eyes can be due to
1. harmful rays due to sun
4.Vitamin and antioxidant deficeincy.
It will be important to rule out all these causes first.You need to consult a dermatologist
Drink plenty of water and eat fresh fruits.
You need to apply a sunscrren at day time on regular basis.
At night you can apply combination of kojic acid
and vitamin c
You can also go for chemical peels
which will give a good skin tone.
Hope this will help you.Take care.