The reason is that D&A don't do Continuous Wear lenses for my prescription. Boots do, however it's down to the size (Diameter) and shape (Base Curve) of my eye that determines whether they can supply them.
I'll still need to have an appointment with them to gauge the exact fitting of the lens.
I switched to lenses in the first place to get rid of the inconvenience of having glasses. So I'm getting used to wearing lenses, and now I want to get rid of the inconvenience of the 'takeout/clean/sleep/putin' routine. Oh, and the fact that I feel like clawing my eyes out in the evenings!
It's the cheaper alternative to surgery anyway!!
Update: I have an appointment with Boots in a fortnight! ;o)