Whether a man can still have sex when he is 85 should depend on the actual situation. If you are relatively healthy and have normal sexual ability, you can have sex. If he suffers from some serious lesions, such as cerebral thrombosis, cerebral hemorrhage, etc., he may not be able to have sex.
A man who is 85 years old, belongs to the senior age, is relatively healthy, does not have serious underlying lesions, has a penis that can have normal erection, has normal sexual ability, and can have sex.
Elderly men suffer from some serious lesions, such as cerebral hemorrhage, cerebral thrombosis, etc., which affect the sexual function, the penis can not be erected, or completely paralyzed in bed, losing the sexual ability, and not able to have a normal sex life.
Therefore, whether a man can still have sex at the age of 85 should be determined on a case-by-case basis, and there is no clear standard.