The discussion is more than just about eye damage but also the effects of laser exposure on pilots, and I don't mean
only as a distraction.
The energy density (measure of energy per unit of area) of the laser beam increases as the spot size decreases. This means that the energy of a laser beam can be intensified up to 100,000 times by the focusing action of the eye for visible and near infrared wavelengths. If the irradiance entering the eye is 1 mW/cm2, the irradiance at the retina will be 100 W/cm2. Even a 4% reflection off an optic can be a serious eye hazard. Remember a low power laser in the milliwatt range can cause a burn if focused directly onto the retina.