Average solar irradiance at Earth surface on direct sun is 1050 W/m^2 = 1,050,000mW/10,000cm^2 = 105 mW/cm^2 according to Wikipedia, so indeed 40mW/cm^2 looks like a large value, of course that doesn’t include the eye focusing effects that make seeing the sun on the sky mostly safe, but looking directly to the sun a terrible idea.