In Argyll Robertson Pupil?

The Argyll Robertson (AR) pupil has been defined as a pupil that is small and constricts poorly to direct light but briskly when a target within reading distance is viewed ("light-near dissociation").

Why are pupils small in Argyll Robertson?

Typically, the pupil constricts, or shrinks, in response to bright light and dilates, or expands, in response to dim light. The Argyll Robertson pupil occurs when a disease interferes with the light reflex pathway, thereby inhibiting the pupil's natural response to bright light.

Is Argyll Robertson pupil unilateral or bilateral?

Argyll Robertson pupils (AR pupils) are bilateral small pupils that reduce in size on a near object (i.e., they accommodate), but do not constrict when exposed to bright light (i.e., they do not constrict when exposed to light).