I've just had my eyes tested today, and bought some glasses straight away using the prescription. I usually just wear lenses. I am disappointed to find that my vision is not as clear as it is with contact lenses of the same strength -3.50 right eye, -4.0 left eye. Should the prescription for my glasses differ from the prescription for my lenses? I had hoped for crystal clear vision, but cannot read text on the TV 12 feet away very clearly. I've spent 300 pounds on these glasses and can't see as clearly as I'd anticipated - eek!! Is this to be expected?