Until this Sunday, ALL products on Glasses Direct are VAT FREE with the 17.5% reduction. In addition, click through Quidco for 18% cashback, and check out their designer frame sale for discounts up to 50%.
I'm off for an eye test on Sunday to make sure I can order the frames I want before the discount is up, The frames I've seen are £45 reduced to £34 in the sale (though there are bigger reductions to be had!), with 17.5% discount reducing them further to £28.05 including frames! Even if I don't buy any extras, I'll then get £5.05 cashback! Effective price: £23.00 down from £45.00.
There's also a 10% off voucher on HUKD, but having not been through the checkout process I haven't been able to see if this can be applied on top of the above offers.