Xu R, Gil D, Dibas M, et al. - Researchers conducted the study for analyzing the pupil and visual impact of a single early morning drop of a low concentration miotic. Following bilateral instillation of single drops of 0.1% brimonidine tartate in 19 early presbyopes (40–50 years) and 11 mature presbyopes (> 50 years), pupil size, refraction, visual acuity (VA), near reading performance and intraocular pressure were monitored for 8 h at a wide range of light levels. Most of the pupil miosis remained 8 h after instillation, while near VA improvements vanished after 4 h. Low dose miotics in presbyopic subjects can enhance near vision while retaining high-quality distance vision over a wide range of light levels. Significant improvements in near vision were reported only during the 1–2 h period after dosing when miosis peaked.