S. Genensky; invented vision-boosting devices

Mr. Genensky, a native of New Bedford, Mass., founded the Center for the Partially Sighted in West Los Angeles in 1978.

He was best known for developing a special kind of closed-circuit television that became the prototype for the video magnifiers sold around the world today that enable people with severe visual impairments to read books, magazines, and other conventionally printed materials.

“Sam is universally known as a pioneer of assisted technology for people with partial vision,’’ said Tony R. Candela, a deputy director in the California Department of Rehabilitation who oversees services for the blind and deaf.

Mr. Genensky’s magnification machine “ended up revolutionizing the ability of people with partial vision to read printed material,’’ Candela said.

The positive reaction to the invention persuaded Mr. Genensky to become an advocate for the partially sighted, who number about 14 million in the United States.

“When the partially blind went out in the world, they found that they either got no services at all or services that were appropriate for people who were totally blind,’’ Mr. Genensky told an interviewer this year. “Neither of these alternatives made much sense to me.’’

Mr. Genensky was determined not to be treated as a blind person, even though he met the legal definition. His eyes were burned shortly after birth when a delivery room nurse accidentally administered the wrong eyedrops to guard against infection. No sight remained in his left eye, and he had only 20/1,000 vision in his right eye.

Hard-working and exceptionally bright, he completed the first eight years of school in seven years. After elementary school he was sent to Perkins Institute for the Blind in Watertown, Mass., where he refused to use Braille, even though he knew it. He preferred to use what little sight he had, even if it meant holding a book up to his nose.

Frustrated by teachers’ demands that he “act like a well-behaved blind child,’’ he left Perkins for a regular public high school in New Bedford. To keep up with his normal-sighted peers, he brought his father’s World War I-era binoculars to geometry class one day and was delighted to discover that he could see what the teacher was drawing on the board.

With the help of a doctor, he added another lens to one side of the binoculars, essentially creating a bifocal system that allowed him to read the blackboard as well as the book on his desk. He began to earn A’s.

This contraption, although cumbersome, worked well enough to get Mr. Genensky through high school, as well as four years at Brown University, where he graduated magna cum laude with a bachelor’s degree in physics in 1949. He earned a master’s in pure mathematics from Harvard in 1951 and a doctorate in applied mathematics from Brown in 1958.

In the late 1950s, not long after joining Rand, a colleague, Paul Baran, noticed how Mr. Genensky had to work slumped over his drawing board with his nose to the paper. Baran suggested that there had to be a way to improve the mathematician’s ability to see.

With Baran and other scientist and engineer friends, Mr. Genensky hooked up a closed-circuit TV with a camera. It not only magnified the type on a page, but had controls for brightness and contrast. Mr. Genensky didn’t have to slump over his desk anymore.

When the device was publicized as “Sam Genensky’s Marvelous Seeing Machine’’ in a 1971 issue of Reader’s Digest, the Rand mathematician was flooded with thousands of requests a week from partially sighted people who wanted to try it. Many of them said the magnifying machine enabled them to read printed matter for the first time.

“I couldn’t turn my back on them,’’ he said in 1994, recalling his decision to devote himself to working for the partially blind.

Mr. Genensky leaves his second wife, Nancy Cronig; daughters Marsha and Judy; stepchildren Andrea Cronig Mindell, Mitchell Cronig, and Adam Cronig; and four grandchildren.