The last option is spectrally-selective window film. Premium Spectrally Selective window films allow 60-70% of the natural light to still come in, while simultaneously blocking a lot of heat. It’s hard to tell that there’s anything on there, but you definitely feel much more comfortable. If you need maximum performance but you don’t really want to change the appearance of your widows, this is the best choice. 

 

https://multimedia.3m.com/mws/media/1173225O/3m-sun-control-window-film-prestige-series.pdf?&fn=98-0150-0756-4.pdf

 

In both photos, only the upper angled windows are done, the lower ones are untreated.