Hi!nagaveni,
Welcome To HealthcareMagic forum,
Dark circles is multi factorial,there is no one reason to it..and thats the reason even the treatment has to be a combination of few things .Common reasons for dark circles are
iron deficiency,lack of sleep,stress,thin skin around the eyes(fine lines),less water intake,any chronic illness,excess sun exposure,familial etc.
Various treatments available are-
chemical peels,
hydroquinone cream,tretinoin cream,kojic acid,vit c creams etc.Latest would be use of small tiny injections which would help filling the sunken area around the eyes.Also one can try lasers which are specific for pigmentation like Q-switched Nd:yag laser (1064nm).
Along with this improve your sleeping habits ,drink plenty of water ,use a good sunscreen daily and follow healthy life style .
You should understand that you may not get 100% result with any of the methods ,but improvement is what you should look at and try maintain what results you get.
Consult a dermatologist who can analyse all the causes and has latest facilities for the same.
regards,
Dr.chawda