Louise L. Sloan was an American ophthalmologist and vision scientist. She was a student of Gertrude Rand and had a nearly 50-year long career at Johns Hopkins Wilmer Eye Institute, USA. Her career pioneered and shaped the sub-discipline of clinical vision research. She directed the Wilmer Laboratory of Physiological Optics for 44 years after receiving her PhD from Bryn Mawr College, USA, in 1926 and short stints in Bryn Mawr’s experimental psychology program and the Department of Ophthalmology at Harvard Medical School, USA.

One of her most important articles described applications of newly-devised visual function tests in detecting clinical diseases such as central serous retinopathy. These tests included color perimetry with red and blue test objects on a matching background, the test now known as static perimetry, and tests of visual function for macropsia, micropsia, and metamorphopsia. She also devised various tests for congenital red-green color blindness, especially in connection with the needs of the military.

In 1971, Sloan was awarded the Edgar D. Tillyer Award in recognition of her accomplishments and scientific standing in the field of visual physiology. She was also in the inaugural class of Fellows in 1959.

She was best known for the development and standardization of equipment for visual acuity testing and improvement. She developed the first low-vision clinic at the Wilmer Eye Institute. Her work was based on applying research findings in basic optics and testing these methods clinically.

Sloan died in 1982 at the age of 84.