Mizar ( UMa / Ursae Majoris) is a star in the constellation Ursa Major and is the second star from the end of the Big Dipper's handle. Its apparent magnitude is 2.23 and its spectral class is A1V. Mizar's name comes from the Arabic mzar, meaning a waistband or girdle. With normal eyesight one can make out a faint companion just to the east, named Alcor or 80 Ursae Majoris. Alcor is of magnitude 3.99 and spectral class A5 V. Mizar and Alcor together are sometimes called the "Horse and Rider," and the ability to resolve the two stars with the naked eye is often quoted as a test of eyesight, although even people with quite poor eyesight can see the two stars.
The ancient eye test for those wishing to join the Roman army was administered using stars in the handle of our modern-day Big Dipper. If you passed, you got a job as an archer. If you failed, you had to serve in another capacity … perhaps as a cook. It’s said that sultans of the past also tested their soldiers’ eyesight in this way.