Originally Posted by
Herbie65
But what kinds of tests are they using to check this?
I've had catarct surgery this summer and they just performed all the usual checks at the aeromedical center where I have been going since 15 years (also EASA). All these halo, starburst, glare and whatever else effects are subjective, you either see it or you don't, but I wouldn't know how anyone could detect that with an instrument.