General Antonyms:
* Intact: Meaning whole, complete, or undamaged.
* Sound: Meaning healthy, in good working order, or unimpaired.
* Unimpaired: This is the direct opposite of impaired.
* Functional: Meaning capable of working or operating normally.
Contextual Antonyms:
* Enhanced: Meaning improved or strengthened. (If talking about impaired vision, the antonym might be enhanced vision.)
* Improved: Meaning made better or more effective. (If talking about impaired cognitive function, the antonym might be improved cognitive function.)
* Restored: Meaning returned to a former state. (If talking about impaired mobility, the antonym might be restored mobility.)
To choose the best antonym, consider the specific meaning of "impaired" in your sentence.