Overall, the health needs of women in Bangladesh take a back seat to those of men. “In our male-dominated society, when the man has a problem, it requires immediate attention, but women, they can wait,” she said.

But the effects of declining vision can be especially pronounced for women, who are often responsible for earning extra income for their families in addition to the child care and household chores, Ms. Mahjabeen said. “When it takes longer to sew and clean, or you can’t pick out all the stones from the rice, in some households it results in domestic violence,” she said.

VisionSpring distributes more than two million pairs of glasses a year throughout South Asia and Africa, up from 300,000 in 2018.

The study in PLOS One builds on previous research involving tea pickers in India that found a significant jump in productivity among study participants given reading glasses. The paper, a randomized study published in The Lancet Global Health in 2018, documented a 22-percent increase in productivity among workers who had been given glasses. For those over 50, productivity increased by nearly 32 percent.

Agad Ali, 57, a Bangladeshi tailor in the town of Manikganj, was among those who received a pair of glasses as part of the study that was published this week. In an interview conducted by a community health worker and sent via email, he described how worsening presbyopia had made it increasingly hard to thread needles and stitch clothing, adding to the time required to finish each tailoring job. Over time, he said, some customers went elsewhere, and his income began to decline. “It made me feel very helpless,” he said.

Since receiving the glasses, he said, his income had doubled. “These glasses are like my lifeline,” he told the community health worker. “I could not do my job without them.”