Hi, I'm not a pilot (I would if my eyesight was better and I could afford it though...have to stay as an enthusiast for now!), but a higher education dyslexia specialist, so I may be able to help with the definitions etc.....
Gorgophone...that's called scotopic sensitivity. There are tests to work out exactly which colour overlay should be recommended when reading books. The tints require a test by an optometrist with a special machine and may be a different colour from the overlay.
Dyslexia is a frankly crap term which covers a multitude of issues....generally "specific learning difficulty" is preferable. The test for dyslexia (often the Wechsler Adult Intelligence Scale (WAIS) 3) is administered by a suitably qualified chartered psychologist and consists of a range of cognitive performance tests. Someone without dyslexia will normally produce reasonably consistent results, but someone with the condition will produce a "saw tooth" profile. The thing to remember is that everything is comparative to the rest of an individual's performance: someone's lowest score may be higher than your highest, but because of the variations in their results, they will still have dyslexia despite being able to have you for breakfast! Generally, people with dyslexia will often have a comparitively poor short term memory (e.g. problems remembering long lists of numbers, "loose" words they are thinking of before they can be used in a sentence). Many people also have issues taking in the context of written text quickly and then of course there is the old left/right and spelling problems: e.g. muddle up "b"/"d"s and "p"/"q"s, miss syllables out of words, have trouble with double letters and spell phonetically....if you have trouble spelling words like necessary (two similar "ssss" sounds spelt differently!) you may be one of the dyslexic club.
Benenfits of dyslexia can include enhanced visual logic, unnaturally strong long term focus on a specific task, strong 3D spatial awareness and long term/photographic store of information (is this a job description for ATC??!!). Business vision can also be enhanced (hey, My Branston!)
I would guess that these would also be highly beneficial for a pilot: the only downsides (which an aware indiviual could easily deal with) would be being seen as a "different" thinker as regards CRM, sky glare from scotopic sensitivety, the left/right issue and remembering number chains. The only one that might bother me would be if a n individual with poor visual processing had to read and understand a rarely used SOP in a pressing emergency situation (but that's what the sim is for?!). Otherwise, I think that the failsafe nature of flying (e.g. most activities called out and confirmed verbally) will pick up dyslexic (and non dyslexic errors).
Funny old world, isn't it? You often hear people dispairing of their spelling, but you never hear anyone moaning about their 3d spatial awareness being crap!!
Hope this is useful and I'd be interested to hear what others think.
Daniel