Dr. Bruce P. Rosenthal, chief of low-vision programs at Lighthouse International in Manhattan, which offers services for people with vision loss, said the portable magnifiers, with their built-in illumination and powerful electronics, have many advantages over traditional optical devices like magnifying glasses. “Optical devices can’t increase the contrast like these devices,” he said. “Loss in contrast causes as many problems as loss of visual acuity.”

Electronics in the new devices can make black print darker, or switch black lettering on white to white lettering on black  which some people with macular degeneration prefer.

Dr. Rosenthal said the devices could help people with low vision continue with their normal rounds  for instance, shopping in the supermarket or reading a prayer book at a religious service. “One of the concerns we have in working with the visually impaired is depression,” he said. The more that people can complete everyday activities like everyone else, he added, “the more they can cope and feel that their lives are no different than others.”

The devices have a substantial drawback, however, when compared with a $40 magnifying glass: They typically cost $700 to $1,300, and Medicare and most private insurance plans usually do not pay for them, said Robert McGillivray, low-vision specialist at the Carroll Center for the Blind in Newton, Mass.

Image The SenseView Duo is used to read a newspaper and map.

“But if the devices get you back to work, or help you with your education, or increase your pleasure in reading,” he said, “it’s well worth considering them.”