Rising healthcare costs and increasing demands for health care require techniques to choose between competing uses and even rationing of health care. Economic evaluations and health technology assessments are increasingly a means to assess the cost effectiveness of healthcare interventions so as to inform such resource allocation decisions. To date, the adoption of health technology assessments, as a way of assessing cost effectiveness, in ophthalmology has been slower, relative to their implementation in other specialities. Nevertheless, demands for eye services are increasing due to an ageing population. The prevalence of conditions such as glaucoma, cataract, diabetic eye disease and age-related macular degeneration increases with age, and it is predicted that global blindness will triple by 2050. So there is a challenge for ophthalmologists to ensure that they can contribute to, interpret, critically evaluate, and use findings from economic evaluations in their clinical practice. To aid this, this article serves as a primer on the use of health technology assessments to assess cost effectiveness using economic evaluation techniques for ophthalmologists. Healthcare systems face many challenges worldwide – changing demographics and evolution of new technologies are only going to intensify. With this in mind, ophthalmology needs to be ready and able to engage with health economists to prepare, interpret, critically evaluate and use findings of economic evaluations and health technology assessments.