In an intact eye, photoreceptors are unlikely to be the cells with the greatest requirement for lactate as a fuel. First, among all the structures in the retina, photoreceptor cell bodies have the most direct access to glucose. In contrast, Muller cell apical surfaces are recessed below the photoreceptor cell bodies and essentially covered by a carpet of photoreceptors. Based on the physical appearance of this part of the retina, Muller cells’ access to glucose from the IPM would be limited to what is left over after photoreceptors take what they require