Welcome to HealthcareMagic. Its true that exposure to sun fastens ageing of skin and brings in wrinkles
and tan too. So here are some remedies which you asked for ; apply aloe vera
over face and other tanned areas atlaest twice daily after rinsing face properly.Rub papaya pulp(natural skin-lightening agent on tanned skin), then rinse.Exfoliate twice daily with lemon juice and honey. Even orange juice helps to fade a suntan.Slice cucumbers and rub on tanned skin.Or dip cotton pads in cold
milk and run them on tanned skin to help fade.Apply almond paste to face after cleansing, then rinse.Hope these work out well on your dad. Wish him good health.
Tomato juice, also has got some anti tan property.