There are pros and cons to glass and to screen cages (and any combination) depending on where you live, etc.
Screen won't hold the humidity in and its harder to keep the temperature up in them if you live in a cool climate but definitely allows the air to flow. In winter, in cool climates (or in houses with air conditioning in the summer) in the screen cage your chameleon will have to spend more time sitting right up under the light in the basking area to keep warm...but not so in the glass cage.
Many people end up adding plastic to 3 sides of the cage to help keep the humidity up and the heat in....but even with just the front screen in cooler climates, the temperature and humidity will be hard to keep up.
Glass cages help to keep the humidity better and the temperatures can be maintained easier in a cool climate. The airflow can still be good in them but definitely less than in a screen cage. But then in summer, its harder to keep the glass cages from becoming too hot.
Spraying in a glass cage keeps the water contained in the cage while spraying in a screen cage won't contain the water....but then there is the issue of not allowing water to lay stagnant in the glass cages.
Regarding reflections...I have rarely (if ever) seen a chameleon react to the glass. They seem to figure out what they are seeing is themselves.
Regarding health issues with glass...I have never had a chameleon develop a respiratory issue or a fungus from being in a glass cage.
My main concern with people telling people that glass should not be used and screen is the only option is that its not really true. It would be much better to give the pros and cons and take into consideration the circumstances of climate, etc. in the area that the person live rather than to just make a definite blanket statement about it....then the person can make the choice.
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