Many ocular diseases are becoming more common, resulting in blindness that occurs in the back of the eye, which is also known as the posterior segment of the eye. Major blinding diseases include age-related macular degeneration (AMD) and diabetic retinopathy. Often there is inflammation and scarring that causes ocular tissue damage. There is an urgency and much unmet medical need to develop the right medicines and formulations to deliver them to treat posterior-segment diseases. Much medical need could be addressed by helping to prevent further damage and injury and to halt the progression of ocular disease. Direct injections, known as intravitreal (IVT) injections, of therapeutic proteins and the use of steroid implants in the vitreous cavity are currently the best clinical methods to achieve prolonged exposure in the posterior segment. As the molecular mechanisms of diseases have been uncovered, the development of protein therapeutics has significantly increased. There is also an increased focus on making more stable proteins, so they can be formulated and used in long-acting forms to reduce the frequency of IVT injections. Ophthalmic protein-based medicines will continue to be developed as molecular mechanisms involved in blinding diseases become better understood.