Claudius Ptolemy, Gladys West, and Kursat Ceylan were all exceptional leaders in their field. Ptolemy was an ancient astronomer, mathematician, and geographer, who most notably developed the geocentric model. West is a scientist and mathematician best known for her contributions towards the development of the GPS. Ceylan was actually born blind, but this didn't stop him from building the WeWalk cane, a navigation tool that helps people with visual impairment.