I use these, got a clear one and a slightly tinted one on two visors for summer/winter.
Only thing i will say is that you need a clean and dust free enviroment when putting it on, 'cos the double sided tape
will not come off in any decent condition if you foc it up.
You work out exactly where you want it first (tape helps) then bend it from the middle, stick it down and work your way outwards.
They're very good for anti fogging, and even after a few years of wear and tear when the rain gets the better of the tape, all i did was buy some 1mm thick double sided and cut a strip 4mm wide that was long enough to shape around the whole visor in one go, then i put a small blob of clear rubber glue at the join to make it airtight and it was like new again.
**** They have a very slight reactolite lens in sunshine, and also filters (polarizes) headlight glare at night time, which is especially helpful if you already wear glasses too, so it will turn a star shaped glare into just a single beam.
**** http://www.ebay.co.uk/sch/i.html?_trksid=p2047675.m570.l1313&_nkw=Progrip+3000+Visor+Insert&_sacat=0&_from=R40 As for the squashed ear problem, i think that's literally a different make/model of crash helmet issue.
My old Shoei crash helmet had no issues at all with my glasses, but when i bought my Arai it was so fitted around the sides of my eyes i used to have to physically force my glasses on, although that could have also been the fact that it was a new lid.