In Flex, an eReferral can be sent once an examination has been completed.
The Optometrist can view the data that makes up the referral, as well as add any additional notes (this data can be sent to one of several referral systems in England. The system you use varies depending on your location in the country).
Once the data has ben sent, the referral can be completed in the online Referral system.
Practices can check on the status of a referral in the NHS England section of Business Intelligence.