• In an attempt to determine whether autonomic neural factors might be involved in senile miosis, we tested pupillary responses to agents acting on the ocular sympathetic system in old subjects and compared them to responses in young adults. Our results suggest that sympathetic tone is decreased in the elderly. The dilator pupillae muscle does not lose its sensitivity to norepinephrine with age.
Korczyn AD, Laor N, Nemet P. Sympathetic Pupillary Tone in Old Age. Arch Ophthalmol. 1976;94(11):1905-1906. doi:10.1001/archopht.1976.03910040615006