Tomatoes have moisturizing and regenerating properties and it can help contribute in getting rid of dark circles. Other benefits of tomatoes are:

Fades dark spots and blemishes. Smoothens out rough skin
Slow down the aging process of skin. Fight off free radicals that cause fine lines and damage to healthy skin cells.
Helps build up collagen and maintain skin tautness and elasticity.
Composes the uppermost layer of skin. Heals dry withered skin.
Solves dry skin by moisturizing and hydrating skin cells.
For youthful radiant skin. Slows down the aging process of skin.

Lemons are a natural antiseptic and can prevent diseases and allergies. Lemons can be successfully used for oily or mixed types of skin that have enlarged pores. They can also be useful for removing stains or freckles.

Squeeze the juice from the tomato and lemon into a bowl.
Mix them together really well with a spoon.
Apply this mixture carefully under your eyes before washing your face. You can apply the mask to your whole face as well.
Leave on for an hour and then rinse it off.