A serious infection inside the eye that can cause permanent blindness — a known risk of intravitreal injection even when performed correctly.Infection of the vitreous and aqueous humor by bacteria or fungi. Occurs as a complication of intravitreal injection even under sterile surgical conditions in clinical settings. Incidence with anti-VEGF intravitreal injections is approximately 0.03–0.05% per injection in clinical practice — low, but not zero, and the consequence is potentially catastrophic. This is one key reason intravitreal injection is not an appropriate self-experimentation route under any circumstances.