I realise that wearing sunglasses is a very personal thing. In 46 years of professional flying including years of flying and living in the desert (Libya, Aden, Bahrain and Oman) I have never, ever worn sun glasses.
I have always relied on the baseball cap and/or the sunvisor in the aeroplane if needed.
I can remember doing my first medical in Aden with our MO (where are you Russ Martin) and he asked to see my sunglasses. "Haven't got any" said I. "That's good" said he. "They lull your eyes into a false sense of security and mostly don't stop the damaging UV light". I still have 20/20 eyesight at the age of 71.
In my spare time I used to spend all day out in the sun at the gliding club at Sheik Othman without a problem. In fact, not many of us wore sunglasses. Obviously some people absolutely have to wear sunglasses and I fully accept that the sun at White Waltham is much stronger than it is in the Middle East but I can only speak from my half a century of experience.