There's an article (subscription required) about "doctor only" contact lenses in today's Wall Street Journal.
People who have ever purchased contact lenses online know that the optometrist charges a huge markup on lenses. You can buy the same lenses online for a fraction of the cost.
It seems that doctors and certain contact lens manufacturers have been trying to boost profits by establishing lines of "doctor only" lenses which can only be purchased from an opthamologist or optometrist. Obviously, the doctor can increase profits by prescribing these lenses because his patients can't buy them cheaply on the internet.
Yet another example of how the healthcare business tries to increase profits by preventing free market competition.