The advent of the discipline of molecular genetics over the past decade has led to a dramatic growth in our understanding of the genetics of a myriad of diseases. Ophthalmology has benefited greatly from this new technology, with significant advances in our knowledge about conditions as varied as aniridia and retinitis pigmentosa.1 2 Our understanding of the genetics of primary open angle glaucoma (POAG) may not be as clear as with some other ophthalmic conditions but, nevertheless, there have been great advances since the last review about the genetics of glaucoma published in the BJO in 1980.3 At that time, our knowledge was based on a number of conflicting studies attempting to link human polymorphisms, such as the ability to taste phenyl thiocarbamide, with glaucoma.4 Nowadays, the positions of genes responsible for various forms of glaucoma have been localised, not just to individual chromosomes, but to specific small regions on those chromosomes. Recently, for the first time, a gene responsible for a specific form of POAG has been identified. This review aims to highlight and explain the important recent advances in our understanding of the genetics of POAG.