In 1996 the Excise Tax Act, covering the way GST and HST was applied to medical and assistive devices, was changed.  Prior to the change specialized equipment for low vision and blindness was considered exempt from Federal sales tax based on its purpose of manufacture. 

A device manufactured specifically for the purpose of aiding someone who was blind or who had low vision was exempt from Federal tax at time of sale.  In provinces with PST it was also exempt from PST.

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