Dropping a noun and keeping the adjective in a contrast sentence

This sentence is parallel and correct: "Eyes with an average rating of >= 4.0 were included in the attractive cohort, while eyes with an average rating of <= 2.0 were included in the unattractive cohort."

Can this be rewritten more concisely and still be grammatically correct as "Eyes with an average rating of >= 4.0 were included in the attractive cohort, while those with <= 2.0 were included in the unattractive."

Does this violate parallelism? Is it clear that "those" refers to eyes with average ratings? Is it fine to end the sentence with the adjective unattractive without adding cohort to the end of it?