The receipts from selling contact lenses, eye glasses, eye glass frames and lens glass to ophthalmologists and optometrists may be deducted from gross receipts if the buyer delivers a nontaxable transaction certificate to the seller. Contact lenses, eye glasses, eye glass frames and lens glasses are "prosthetic devices" within the meaning of Section 7-9-73 NMSA 1978.
N.M. Admin. Code § 3.2.232.8