Eye fatigue with vortex???

[Duckhunterbrad]

I am looking at getting the 11-33 vortex razor hd and the 20-60 razor hd. I currently use a Nikon and can only use it an hour or so before I notice eye fatigue and get a headache. I am fairly stuck on buying the 11-33 just for packing purposes, but was wondering if I needed to go with a Swarovski/Leica/zeiss on the bigger scope to prevent such eye fatigue? I would need to save for a little while longer to go with a Swarovski and would most likely purchase a used unit.