An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Rothwell SE, Campbell FW.Rothwell SE, et al. Among authors: campbell fw.Ophthalmic Physiol Opt. 1987;7(2):161-3. doi: 10.1111/j.1475-1313.1987.tb01014.x.Ophthalmic Physiol Opt. 1987.PMID: 3658441
Artigas JM, Felipe A, Campbell FW.Artigas JM, et al. Among authors: campbell fw.Ophthalmic Physiol Opt. 1988;8(1):63-6.Ophthalmic Physiol Opt. 1988.PMID: 3419830
Prydal JI, Artal P, Woon H, Campbell FW.Prydal JI, et al. Among authors: campbell fw.Invest Ophthalmol Vis Sci. 1992 May;33(6):2006-11.Invest Ophthalmol Vis Sci. 1992.PMID: 1582805