I would recommend that you attain clinical experience in several different environments. It's not whether you can treat or not treat. In your formative clinical years, you should seek a clinical experience where there is plentiful glaucoma clinical material. This is the arguement that many ophthalmologists have about optometrists in general is that they don't see the "thousands" of patient encounters. In some respects this is a valid point.
NOTHING beats numbers of clinical encounters. There is no use going to a "wide open" state if you don't see glaucoma patients and cannot get the experience of senior expertise either from optometrists or ophthalmologists or both.
Seek also clinical experiences that expose you to the USE of advanced technology in clinical decision making. Unfortunately or fortunately, technology has assumed a central place in glaucoma care and it must be mastered.
Richard