Astigmatism of the Ex Vivo Human Lens: Surface and Gradient Refractive Index Age-Dependent Contributions.
Birkenfeld J, de Castro A, Marcos S. Astigmatism of the Ex Vivo Human Lens: Surface and Gradient Refractive Index Age-Dependent Contributions. Invest Ophthalmol Vis Sci. 2015 Aug; 56(9):5067-73.