Mydriasis

Technically, drugs that cause miosis can relieve the PNS effects of those causing mydriasis since sympathetic and parasympathetic stimulation tend to negate each others' effects.

Finally it must be added, that if the ophthalmoscopic estimation of refraction is to be exact, mydriasis by atropine is required, when, as is known, even emmetropic eyes may show a slight degree of hypermetropia.