Exhibit 16.1

Letter from Marcum LLP dated October 10, 2025

FORM 8-K ATTACHMENT - CHANGE OF ACCOUNTANTS’ LETTER

October 10, 2025

Securities and Exchange Commission

100 F Street, N.E.

Washington, DC 20549

Commissioners:

We have read the statements made by Syntec Optics Holdings, Inc. under Item 4.01 of its Form 8-K dated October 10, 2025. We agree with the statements concerning our Firm in such Form 8-K; we are not in a position to agree or disagree with other statements of Syntec Optics Holdings, Inc. contained therein.