EX-5.1

Exhibit 5.1

Hogan Lovells US LLP

1735 Market Street, Floor 23

Philadelphia, PA 19103

T +1 267 675 4600

F +1 267 675 4601

www.hoganlovells.com

October 20, 2023

Board of Directors

EyePoint Pharmaceuticals, Inc.

480 Pleasant Street

Watertown, MA 02472

Ladies and Gentlemen:

We are acting as counsel to EyePoint Pharmaceuticals, Inc., a Delaware corporation (the “Company”), in connection with its registration statement on Form S-8 (the “Registration Statement”), filed with the Securities and Exchange Commission under the Securities Act of 1933, as amended (the “Act”), relating to the proposed offering of an aggregate of 9,538,390 shares of common stock, par value $0.001 per share (“Common Stock”) of the Company (the “Shares”), consisting of (a) 9,364,690 shares of Common Stock issuable pursuant to the EyePoint Pharmaceuticals, Inc. 2023 Long-Term Incentive Plan (the “2023 Plan”), and (b) 173,700 shares of Common Stock issuable pursuant to nonqualified stock option awards granted to employees of the Company to induce each such employee to accept employment with the Company (the “Inducement Awards”). This opinion letter is furnished to you at your request to enable you to fulfill the requirements of Item 601(b)(5) of Regulation S-K, 17 C.F.R. § 229.601(b)(5), in connection with the Registration Statement.

For purposes of this opinion letter, we have examined copies of such agreements, instruments and documents as we have deemed an appropriate basis on which to render the opinions hereinafter expressed. In our examination of the aforesaid documents, we have assumed the genuineness of all signatures, the legal capacity of all natural persons, the accuracy and completeness of all documents submitted to us, the authenticity of all original documents, and the conformity to authentic original documents of all documents submitted to us as copies (including pdfs). As to all matters of fact, we have relied on the representations and statements of fact made in the documents so reviewed, and we have not independently established the facts so relied on. This opinion letter is given, and all statements herein are made, in the context of the foregoing.

This opinion letter is based as to matters of law solely on the Delaware General Corporation Law, as amended. We express no opinion herein as to any other statutes, rules or regulations.

Based upon, subject to and limited by the foregoing, we are of the opinion that following (i) effectiveness of the Registration Statement, (ii) issuance of the Shares pursuant to the terms of the 2023 Plan or the Inducement Awards, as applicable, and (iii) receipt by the Company of the consideration for the Shares specified in (x) the resolutions of the Board of Directors, or a duly authorized committee thereof, (y) the 2023 Plan and (z) the applicable award agreements, the Shares will be validly issued, fully paid, and nonassessable.

Hogan Lovells US LLP is a limited liability partnership registered in the State of Delaware. “Hogan Lovells” is an international legal practice that includes Hogan Lovells US LLP and Hogan Lovells International LLP, with offices in: Alicante Amsterdam Baltimore Beijing Brussels Caracas Colorado Springs Denver Dubai Dusseldorf Frankfurt Hamburg Hanoi Ho Chi Minh City Hong Kong Houston Johannesburg London Los Angeles Luxembourg Madrid Mexico City Miami Milan Minneapolis Monterrey Moscow Munich New York Northern Virginia Paris Perth Philadelphia Rio de Janeiro Rome San Francisco São Paulo Shanghai Silicon Valley Singapore Sydney Tokyo Ulaanbaatar Warsaw Washington DC Associated offices: Budapest Jakarta Shanghai FTZ Zagreb. Business Service Centers: Johannesburg Louisville. Legal Service Center: Birmingham. For more information see www.hoganlovells.com