Generally, as to the other services, it is unclear as to whether there is a contract at all. To have a contract, you need to agree on the basic elements, one of which is price.
However, there are other theories of recovery, including unjust enrichment (you received the services and should be required to pay something) and quantum meruit ( he should receive the fair value of what he provided).
Any way you look at it, he should provide you with a breakdown of the services and their cost so you can confirm that you received them and that the fee is reasonable.
Seems clear you owe the $112.
No lawyer needed here because the amount at issue is too small, even if he sends you to collection, which he might do. That might violate other laws and may require an attorney.
The amount you owe the optometrist will depend on the contract that you signed. If the amount above the $112 minimum consultation fee that you agreed to pay is excessive, you may want to consult a business lawyer about your rights. However, if the amount is small, you would be better off settling with the optometrist. You do not want the consultation fee with the attorney to exceed the amount you will be able to recover from the optometrist.
Disclaimer: This answer is provided for informational purposes only, does not constitute legal advice, and does not create an attorney-client relationship. Actual legal advice can only be provided after completing a comprehensive consultation in which all of the relevant facts are discussed and reviewed.