space.com
Nov 14, 2026
Think you have good eyesight? Try counting the stars in the Pleiades tonight
AI-summarised brief · reviewed before publication
Every November, the author conducts a personal “eyesight test” by counting stars in the Pleiades cluster, noting how visibility changes with dark adaptation and observation techniques. The Pleiades, about 444 light‑years away, are a nearby open cluster of roughly 1,000 young stars. The author describes counting the brightest stars, waiting ten minutes after leaving a bright environment, and then using binoculars and averted vision to reveal fainter members. The exercise highlights how perception, sky brightness, and eye adaptation affect naked‑eye astronomy.
💡 Why It Matters
- · The practice demonstrates the limits of human vision and the importance of dark adaptation for amateur astronomy, offering a simple, repeatable method to gauge observational skill.
