Visual capabilities recovery for some kind of illness is possible through subretinal implantable device stimulation. Two possible approaches for retinal pixel are proposed, fabricated in 0.35mum CMOS, tested and compared including electronic response on a human tissue like interface. In these solutions, power consumption has been proved to be dominated by electrode stimulation and, in normal condition, typical consumption is below 1 mW. The proposed pixel architectures, with 120 mum (LICOS) and 100 mum (WATCH) inter-pixel step, provide the smallest, standalone, highly integrated, subretinal implantable chip ever reported.