Abstract: Epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence. DNA methylation is an important part of epigenetical changes and has been reported to be associated with diseases. The methylation of CpG islands in DNA sequences can inactivate a promoter and thereby silence gene expression. DNA methylation is reversible and the demethylation drug intervention can reshape gene expression and thereby reverse the occurrence and development of a number of diseases. The study of DNA methylation in ophthalmic diseases can provide new ideas for the pathogenesis and therapy development. (Int Rev Ophthalmol, 2014, 38: 170-174)