Eyes can be done at any age, but I prefer to leave mine until they are 18 months old, or thereabouts. This gives the eyes a chance to 'mature'. It's also best to make sure that you check them on a yearly basis. I don't have Welsh Springers, I have large Munsterlanders, so don't know if you are checking for any particular problem (sorry about my ignorance ;) )
My male munster was hip- and elbow-scored at 3 1/2 years old. His results were excellent, so unless you think there may be a problem there is no rush to get them done early. The earliest you can get them done is 12 months.