Eye test - Cost me 15 CHF at the optician across the road from the Strassen Verkhersamt in Steinhusen, Zug. No appointment, just walked in.

As noted by many here the rules, regs etc are pretty much spot on, but....

In my own case I got slack and never did the license change thing untill 5 years after I got here. Converted my expired Aussie lic and current Turks and Caicos Islands licence to a swiss lic. the Lady at the strassen verkhersamt grumbled a fair bit, and 3 days after i left it in their hands I got a call asking me where Turks and caicos was (Caribbean if your wondering). 4 days later my swiss licence arrived in the mail.
True story folks.

My wife changed her valid aussie to swiss 4 years after she should have. (Before me even). I have friends with similar experiences

Now then, what I learned from this is that it all depends on who you deal with at the Strassenverkhersamt on the day, how nice you are to them and how apologetic your appear when grumbled at .

The Swiss love thier rule book, no denying it, but they also get a small kick out of bending the rules from time to time too I think . Its thier way of being naughty