Ingraham H, ed. American Academy of Ophthalmology. 2017-2018 Basic and Clinical Science Course. San Francisco: American Academy of Ophthalmology; 2017; v.1-13.
Eyeglasses for vision correction. American Academy of Ophthalmology. https://www.aao.org/eye-health/glasses-contacts/glasses. Updated December 12, 2015. Accessed July 2019.