Itâs Not the Needle That Hurts. I believe the pain is due to the solution used to clean the eye prior to the injection and not the needle itself. The solution is called âBetadineâ and is commonly used to cleanse the eye prior to intraocular injection. Most retina specialists use this a part of their routine.
For numerical convenience, an object brighter than 0th magnitude has a negative magnitude; the brightest star, Sirius is magnitude -1.4; the full moon is magnitude -13, and the Sun is a blazing -26th magnitude.
Absolute magnitude measures the intrinsic brightness of a celestial object rather than how bright it appears on Earth, using the same logarithmic scale as for apparent magnitude. Sirius has an absolute magnitude of 1.5, considerably dimmer than Rigel which, though its apparent magnitude is 0.12, has an absolute magnitude of -8.1. Stars that appear dim in the night sky but have bright absolute magnitudes are much farther from Earth than stars that shine brightly at night but have relatively dim absolute magnitudes.