Four words have been given, out of which three are alike in some manner and one is different. Select the word that is different.

Ecology

Myology - it is the study of the structure , arrangement and action of muscles

Dermatology - it is related to the treatment of skin disorders

Ecology - it deals with the relations to one another and to their surrounding.

Ophthalmology - it is related to the treatment of disorders and diseases of the eye

Except Ecology , all others are related medical term and ecology is related to the study of field