oculist vs medical specialist

oculist and medical specialist both are nouns.

Word	Noun	Adjective	Verb	Adverb
oculist	Yes	No	No	No
medical specialist	Yes	No	No	No

As nouns, medical specialist is a hypernym of oculist; that is, medical specialist is a word with a broader meaning than oculist:

oculist: a medical doctor specializing in the diagnosis and treatment of diseases of the eye
medical specialist: practices one branch of medicine

Other hypernyms of oculist include specialist.

oculist (noun)	medical specialist (noun)
a medical doctor specializing in the diagnosis and treatment of diseases of the eye	practices one branch of medicine
a person skilled in testing for defects of vision in order to prescribe corrective glasses