Can presbyopia be prevented?

No. Presbyopia is the difficulty for near reading vision with age, usually after age 40 but in myopic or nearsighted people they can see up close so they dont have that problem but ofcourse they dont see far clearly an when you correct the far vision with glasses they again cannot see near without bifocals.
No. If it is going to happen, it is going to happen. Aging eyes=aging lenses. Stiff lenses to my knowledge cannot be prevented. Buy you some sexy reading glasses, accept it and move on! Maybe if you have cataracts you can get some of these new implanted lenses and keep your vanity? Look on the far side!

Related Questions

How is presbyopia prevented?

Currently impossible. This is a natural age related hardening of the lens of the eye. It cannot be prevented by any currently known method (just as grey hair cannot be prevented). Your ophthalmologist can help you with advice and devices to compensate.