There are three types of lens replacement for cataracts, the NHS only fit the cheapest and under NHS rules you can not make a cash contribution to any NHS treatment by law. Therefore if you want the best new lenses, work like natural lenses for focusing you have to pay for the complete operation which will be over £2000 each eye.
I believe on sunglasses for flying a brown/gold tint is the best as we are more sensitive to black/yellow contrasts than black white that is why wasp/bees and other nasty things are these colours see and avoid rule.