Christian Ladd-Franklin, an American scientist and known for her valuable contribution to the theory of color vision. Christine Ladd (1847-1930) followed her interest in mathematics at the newly Johns Hopkins University, but despite meeting all of the prerequisites for a PhD in 1882, she was denied the degree due to her gender (Hergenhahn & Henley, 2019). During that period, women were not offered a degree or the ability to observe both genders with equality through the same glass. Although, she received an honorary degree from Vassar in 1887. She was able to pursue her interest in the subject of psychology that she had cultivated earlier after her marriage to Fabian Franklin, a mathematics professor at John Hopkins. In the year 1887, she wrote a paper on vision.