A long long time ago when I was applying to study in Universities, a lecturer showed us a demonstration with a laser. As an aside, he told us to look at the pattern projected by the laser onto the wall and do something which I forget (move your head from side to side or something), and if the pattern stayed still you had 20-20 vision. Does anyone know the details?

--
The best engine in the world is the vagina. It can be started with one finger, self lubricates, takes any sized piston,
then every 4 weeks it does it's own oil change. It's just a pity that the management system is so ****ing temperamental! -- Dr. Hermann Otto Kloepneckler, M.D., Ph.D.