sclera vs albuginea

sclera and albuginea both are nouns.

Word	Noun	Adjective	Verb	Adverb
sclera	Yes	No	No	No
albuginea	Yes	No	No	No

As nouns, albuginea is a hypernym of sclera; that is, albuginea is a word with a broader meaning than sclera:

sclera: the whitish fibrous membrane (albuginea) that with the cornea forms the outer covering and protection of the eyeball
albuginea: whitish tunic

sclera (noun)	albuginea (noun)
the whitish fibrous membrane (albuginea) that with the cornea forms the outer covering and protection of the eyeball	whitish tunic