A bit off-topic for Covid, but after a recent (regular) eye-test for short-sightedness about a fortnight ago, the optician was rather concerned (as was I) about some symptoms that I'd developed over the last year or so -- the last six or seven months in particular.
Anyway, he referred me to a consultant at the local eye hospital, who diagnosed it as something called
Thyroid Eye Disease, (T.E.D.)which is a nuisance, and can turn nasty if not treated, but is no big deal. Radiotherapy some years ago fried my thyroid gland, and while I take Thyroxine, T.E.D. is apparently a not-uncommon consequence of any thyroid disorder. It causes inflammation and swelling in the muscles and tissues around the eyes, and causes sore eyes, double vision, sensitivity to light, and all sorts.
I was quite impressed -- less than two weeks from the appointment, and it's been diagnosed and the consultant has ordered a lot of tests, scans and referrals (all under the NHS) to various specialists (MRI scan, endocrinologist, prism for my glasses to correct for double vision, and so on), plus given me a prescription (free, because of my age) for some pretty expensive eye drops and ointments.
I've had to buy my own Selenium supplement, though but since that's only a few £ for several weeks' supply, I don't mind.