Ocular injection (intravitreal, subretinal, or into the anterior space) is an efficient approach to deliver many classes of drugs, cells, and other treatments to various cell types of the eye. In particular, subretinal injection is efficient since delivered agents accumulate as there is no dilution due to transport processes or diffusion and the volume of the interphotoreceptor space (IPS) is minimal (10–20 μl in the human eye, less than 1 μl in the mouse eye). We previously reported methods using subretinal injection and electroporation to deliver DNA to photoreceptor and retinal pigment epithelium cells in retinas of live mice (Johnson et al., 14:2211–2226; Nickerson et al. 884:53–69, 2012; Andrieu-Soler et al. 13:692–706, 2007). Here we detail further optimization of that approach and additionally report its use in delivering DNA expression plasmids to the corneal endothelium.