The term 'Iris Holder' is a combination of two crossword solutions, UVEA and 4 letters. UVEA is the colored part of the eye that controls the amount of light entering the eye. It is made up of muscles, connective tissue, and pigmented cells. The 4 letters refer to the holder, which is an instrument used to hold the iris in place during surgery. This instrument is typically made of metal and is designed to fit securely around the iris.