Thread: Swarovski Z5 3.5-18 problem?

I have the Z5 and was sighting in the other day when I noticed that a ‘casual’ look through the scope was fine but when ‘concentrating’ for a shot I found that my sight picture slowly closed in (like a tunnel shrinking) til everything went black. Now I wear multi-zone glasses and it was a bright day so I assumed it was a problem with my glasses not being positioned correctly due to shooting into the sun. The scope was marginally better at low power and definitely worse at high power.
My lad took it out this morning and came frustrated as he couldn’t get a shot off comfortably at about 250m and he described the same problem. Definitely not sunny this morning and he doesn’t wear glasses.
Any ideas, experience and how do you access warranty if needed? Thanks