Ill. Admin. Code tit. 86 § 130.1980
When optometrists sell tangible personal property to purchasers for use or consumption apart from their rendering of service as optometrists, they incur retailers' occupation tax liability. This is the case, for example, where optometrists sell spectacles, frames, or mountings, without examination or treatment of the eyes, to purchasers for use or consumption, or where optometrists sell such items as sunglasses, cleaning solutions for lenses, barometers, telescopes, field glasses, opera glasses, or other tangible personal property to purchasers for use or consumption apart from their rendering of service. For information about whether these items qualify as medical appliances, see 86 Ill. Adm. Code 130.311.
Optometrists are engaged in professions and primarily render service. To the extent they engage in such profession, they are not engaged in the business of selling tangible personal property to purchasers for use or consumption within the meaning of the Retailers' Occupation Tax Act. Consequently, they are not required to remit retailers' occupation tax measured by their receipts from engaging in such professions, including receipts from both services and tangible personal property transferred incident to those services. However, to the extent tangible personal property is transferred incident to service, optometrists may be liable for service occupation tax.
Ill. Admin. Code tit. 86, § 130.1980