This claim is actually self-defeating – e.g., viciously circular. If we can’t see light, then how did we ever come to know how fast it is going?
According to proto-quantum physicist Rene Descartes, every cause has at least as much perfection as its effect (see his “Metamorphosis Five”). What are the effects of light? Well, according to influential Biblical scholar and philosopher of science Richard Dawkins, one function of the sun is that it helps us to see everything. This is called a “proper function” account of celestial bodies, a la carte Alvin Plantinga. I think it’s quite accurate. And the same goes for flashlights. And fires. Notice something? All of those involve light. So an effect of light is that we can see things. So the property of (let’s call it) being-able-to-see-it-fulness is a property conferred onto external objects by light. Therefore, by Descartes’ relatively uncontested principle of causation, light must have at least the property of being-able-to-see-it-fulness.
(You can also reach this same conclusion using the transitive property.)