Pharmacogenomics is an evolving research discipline within ophthalmology. An early application appears to involve open-angle glaucoma, a common cause of worldwide preventable blindness. Primary open-angle glaucoma is primarily treated with medications, and the two most common classes of drugs are β-adrenergic receptor antagonists and prostaglandin analogs. One small clinical trial has documented a pharmacogenomic relationship between polymorphisms in the β1-adrenergic receptor with the selective β1-antagonist betaxolol. A second small clinical trial has documented a pharmacogenomic relationship between polymorphisms in the prostaglandin F2α receptor and the prostaglandin analog latanoprost. A small pilot study has not found any significant pharmacogenomic relationship between polymorphisms in the glucocorticoid receptor and intraocular pressure elevation following treatment with intravitreal triamcinolone acetonide. Pharmacogenomics may explain some of the well-documented variability in response to common glaucoma medications.