| Cover | Nov. 04, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 4, 2021 |
| Entity File Number | 001-38365 |
| Entity Registrant Name | EYENOVIA, INC. |
| Entity Central Index Key | 0001682639 |
| Entity Tax Identification Number | 47-1178401 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 295 Madison Avenue |
| Entity Address, Address Line Two | Suite 2400 |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10017 |
| City Area Code | 917 |
| Local Phone Number | 289-1117 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | EYEN |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
