In a district where 70 percent of students are below the poverty level and one-third are estimated to be uninsured, many students had been fighting for years through blurred vision and headaches.
"I told my mom it was all blurry," said Daisy, a second grader at Marshall Street, who got glasses this fall from Trujillo. It wasn't just words she had trouble focusing on. It was pictures, TV, the sky, "pretty much everything," she said.
School nurses still conduct basic vision exams on all students, and teachers pick up clues such as squinting or looking at a neighbor's notes.
But when they suspect a vision problem, "really, all you can do is give the parents a letter saying, 'Please take them to the doctor,' " said Whitehall principal Maryanne Hoskins. "There are some instances, teachers have just donated the money to buy the glasses."
And not all kids are like Daisy, recognizing or speaking up when they have a problem.
"Kids are funny at this age. They learn to compensate," Hoskins said. With students who are shy or learning English as a second language, "sometimes it's hard to figure out. Is this a language problem or is there something else going on?"
Susan Oleszewski, who helped spearhead the Eye Institute's charity operation, said that roughly one in four students has a vision problem that could affect academics. That's not only the ability to read the whiteboard, but also to see math problems, work on art projects, or focus for more than a few minutes.
In a 2008 study out of the University of California, San Diego, preschoolers who needed glasses scored significantly lower on tests of their visual and motor skills. After wearing glasses for six weeks, their scores rose to the same level as students with normal vision.
Qay'von, a third-grader at Whitehall, said he had trouble reading before his glasses came in January. "I only looked at the pictures," he said.
Homework takes a little longer now that he's reading the words, but Qay'von doesn't mind. "It's kind of slower," he said, "but I can do it."
Myariah, a third grader at Marshall, said her teacher noticed that her writing has gotten neater with the glasses.
"I kept stopping before," Myariah said. "It was hard to concentrate."
Trujillo said that correcting vision problems early could improve a person's eyesight for life, not because the eyes actually improve but because younger eyes more readily adapt to the corrective lenses.
"After a certain age, if they're in their teens or 20s and they never had glasses," Trujillo said, "they won't be able to see as well, even when you initially put the glasses on their face."
In addition to correcting their vision, Trujillo has found indications of more serious problems in some children. One student had what appeared to be blood spots or hemorrhaging on her retina.
Finding such "back of the eye" problems - which could be symptoms of a more serious illness, such as diabetes, high blood pressure, or head trauma - usually requires eyedrops to dilate the pupil.
Drops make some kids nervous, but Whitehall nurse Linda DiMartin said it could be less scary to do it on school grounds than in a clinical setting.
"We don't want them to have a negative experience with an eye doctor," Trujillo said, adding that he didn't mind sitting and chatting with children - in English or Spanish - until they warmed up to the process.
When they return a few weeks later with the students' custom frames and lenses, "they get these big smiles. . . . It's like magic to them," said Cathie Muhr, an optometric technician.
"I don't like it when I take them off," said Daisy. "It feels funny now."