Any advice please!?

Hello, Upon waking up this morning Bruce’s eye looks very bloodshot & sore. I’ve phoned the vet but unfortunately we cannot get in until Monday. I’ve flushed the eye out with saline & dried it, it doesn’t seem to be bothering him but is there anything else I can/should do? I’ve no clue how this has happened, it was completely fine last night and he’s woken up like it. Anything similar happened to your pooches? TIA for any advice!