Darkness under eyes causes due to multiple reasons like lack of sleep,stress,constant staring at computer screen,vit b12 deficiency,hb deficiency,rubbing of eyes,other skin conditions like acanthosis nigricans.treatment depends on underlying conditions.there are topical creams and skin lightening peels which helps in improving the condition.dry skin on eyebrows occur when there is seborrheic dermatitis which need to be examined.