| Document and Entity Information | Dec. 17, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 17, 2020 |
| Entity Registrant Name | EyePoint Pharmaceuticals, Inc. |
| Entity Central Index Key | 0001314102 |
| Trading Symbol | EYPT |
| Entity Emerging Growth Company | false |
| Entity File Number | 000-51122 |
| Entity Tax Identification Number | 26-2774444 |
| Entity Address, Address Line One | 480 Pleasant Street |
| Entity Address, City or Town | Watertown |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02472 |
| City Area Code | (617) |
| Local Phone Number | 926-5000 |
| Entity Incorporation, State or Country Code | DE |
| Title of 12(b) Security | Common Stock, par value $0.001 |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
