Hi,
You have probably been diagnosed with myopia which is associated with lattices (the weak spots of retina). However,as there have been no symptoms the ophthalmologist has asked you to be vigilant and report SOS in case you notice a flash or floater which is usually indicative of retinal detachment... A condition which if occurs need to be treated to avoid loss of sight.
Next Steps
dilated retinal evaluation....if you had that done and the retina specialist suggested no active treatment except being vigilant...then just relax and carry on normally
Health Tips
meet a retinal specialist at the earliest, if you notice any flashes or floaters.