Seconds.
Only ones needing weighting would be for astigmatic corretion, and that's a recent capability.
I'm paying $400/year for toric multifocals with astigmatic correction.
I tried contacts when I was young but for whatever reason I had too much protein buildup and they were uncomfortable after a few months. I switched back to glasses for a number of years then tried the disposable contacts. Mine are technically extended wear but I take them out every night and I throw them away every few weeks. I haven't had any problem flying with them and I've never had one fall out accidentally. I do carry a spare set of glasses (and a spare package of lenses) but I've never had to use them. As far as my near vision goes, I can tell that it is not as good as it used to be, especially in low light. My eye doctor tells me that for now I should just use a pair of drugstore readers on top of my contacts if I think I need them. When I am wearing my glasses I can take them off and see close up just fine because I am naturally quite nearsighted.
The astigmatic correction is a recent capability, or the weighting? The weighting, could very well be. But toric contact lenses have been around for at least 25 years... I can't prove it, but again, I discussed them with my first optometrist when I started wearing contacts. I never went back to him after my refractive surgery in '93.
That's only about twice what I'd be paying for sphericals if I needed correction on both eyes. So it's more, but not as bad as I thought (3-4 times more).
Astigmatic toric multifocals are recent. Weighting for astigmatics has been around for many decades, dating back to the hard lens days.
I may have to brighten the lights for some stuff (like the numbers in the airport data blocks on sectionals), but that's it. Similar problem in dimly lit restaurants with the fine print on menus.
No problem with the computer at all.
It took several tries to achieve the necessary balance, but we got there eventually. FWIW, my eye doc says my eyes are most unusual, with a gigantic myopic correction in the right eye with a small astigmatic correction, but much smaller myopic correction in the left with a very large astigmatic correction. She says that by the book, I shouldn't be able fuse the image at all with either glasses or contacts, and because I can do both (and go back and forth with only moments of adaption time), she's thinking of doing a paper on me for presentation at an optometric conference.
Also, my large astigmatic correction (over 2 diopters in the left eye) complicates the situation considerably when designing my multifocal contacts. Those without severe astigmatism should have a much easier time of it.
Spherical soft lenses can "correct" small degrees of astigmatism the same way, including astigmatism that is not correctable with cylinder. I have a touch of leftover irregular astigmatism from my refractive surgery which is the reason I wear contacts for distance instead of glasses. It is slight enough that when my spherical correction is plano, it is completely unnoticeable and doesn't affect my ability to read eye charts, but uncorrect me to -1.00 or more and it bothers the heck out of me.
