I'll check out the prices and options on the 1.67 photochromic lenses there. Looking at Zenni Optical's website (the cheapest I have found for regular lenses / frames - and you can read my review of Zenni here) it says that their 1.67 index lenses start at $34.95 and the photochromic lenses are $27.
Legitimate Power. Legitimate power is also known as positional power. It's derived from the position a person holds in an organization's hierarchy. Job descriptions, for example, require junior workers to report to managers and give managers the power to assign duties to their juniors.
ability to get someone to do something you want done or the ability to make things happen in the way you want. position/formal power. set of power mechanisms that a boss (or superior) has the right to make - like demands and imposing consequences that you may not want to follow but have to. legitimate power.