Squinting while texting? Always losing your reading glasses? An eye implant that takes about 10 minutes to put in place is the newest in a list of surgical repairs for the blurry close-up vision that is a bane of middle age. But who’s really a good candidate to toss their specs? “It’s not bringing anybody back to being 20 again,” cautioned Dr. Shilpa Rose, a Washington ophthalmologist who tests whether patients’ eyes are healthy enough to qualify.