I think you would need to research what reflective properties the glass in question has. Different species of reptile have different vision. For example, chameleons are known to attack their own reflection which can result in stress, and water dragons are known to suffer rostral abrasions because of their inability to see glass.
You should be thinking more along the lines of what species is it going to be used with and what implications this might have:
(unless you can cut and make safe the edges of the glass, it is going to be a fixed feature so you will have to account for another means of getting in and out of the vivarium).