I have two such Zeiss lenses, and the aperture control depends on the mount.
On a ZS (M42) mount lens, the aperture is controlled conventionally with a ring on the lens, and there's a stop down lever on the lens so you can open for focusing and stop down for shooting without resetting the aperture on the ring--like on what used to be called a "preset" lens.
On a ZE (EOS/EF mount) mount lens, the aperture is controlled like any EF mount lens with the dial on the back of the camera, and the shutter speed is controlled with the wheel near the shutter button, and the aperture and shutter speed are displayed both on the LCD display on top of the camera and in the finder, and also on the rear LCD for digital cameras, if you set it to display that way.
I can sympathize with the desire for conventional controls, but I've gotten used to the electronic controls and displays on my EOS cameras. I still use them the same way I would any other camera--manual focus, aperture and shutter speed with spot metering.
I'm not sure how the Nikon mount lenses from Zeiss work.