The literature that came with my Laser Pen mentions direct contact between the laser and the human eye. It says what amounts to the aiming of the laser directly into the human eye in excess of 40 seconds "might" cause minimal injury to vision. I would say that the strength of a laser pen is not worth much. Certainly a flash across a human eye for a fraction of a second is probably nothing to worry about. But, I'm not an expert in that regard.
It would surprise me that any Gov't would allow such devices to be widespread sold to the general public if they were to cause significant damage or injury to anything or anyone. As for their affect on an aeroplane, it is unlikely any number of these laser pens striking the fuselage would have even the slightest potential for damage. IMHO