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.
512 raised to the difference of the magnitude s of the objects (since the ~ is logarithmic and the difference in each successive magnitude is a factor of about 2.512 times). For example, a 1st magnitude star is 2.512 times brighter than a 2nd magnitude star (their brightness ration is 2.