Shades Up Forever - but common sense should prevail, where possible!
Being in Canada (YYZ) and loving to travel to NE Asia / SE Asia / South Pacific and totally enjoying the ever changing window view and as such, always a proponent of "SHADES UP" we do try to use a little bit of logical common sense consideration.
When planning trips (leisure) my wife and I always reserve window seats on the starboard side going westbound TPAC and on the port side heading home on eastbound TPAC flights.
Flying from Canada to/from Europe, it's the opposite; PO-SH class!
The above means that on practically all occasions the sun and resulting glare will never enter the cabin through our unshaded windows.
(I presume all travellers here know the origin of PO-SH!)