@Joeblow,
I've a mac, and I do use View sometimes to blow some tiny print up.
My right eye is presently sharp enough (that's the one to have the surgery), but the left, five years from those four surgeries, has waffled into fuzzier - apparently (from the md and my last talk) not all so much from RP, which has been in apparent steady state, nor glaucoma (steady good pressure readings), but from just that messing with the eye four times for a bunch of hours doesn't leave what I'll call good homeostasis, which is a general balance of metabolic goings on. The eye gets tireder, irritated by eyedrops' crud more easily, reacts badly to even mild poking, the odd eyelash, or dryness (best treatment, use hot wet washcloth over eye for a bit), and the lid keeps edging down (lax ligament or tendon, I forget which), while I can still raise it somewhat at will (though it slinks right down again). Meantime the surgeon for that has moved on. (Can't remember if I posted on that, but I'll have the lid fixed if the opportunity arises, depending on medicare paying and if I have sup insurance, somewhere down the line.)
The fear is, of course, that all this happens to the right eye.
I'll try with the Control and plus sign at same time - that could be really good to know. Back when I try it. But there may be some equivalent for Macs..