CSIO’s low-cost, high-powered lens specs to replace conventional ones

To provide an affordable assistive device for patients suffering from severe or functional low vision (FLV), the Central Scientific Instruments Organisation (CSIO) here has developed a high-powered aspheric lens-based spectacles.

Termed as Low-Vision Aids (LVA), the lens has been developed with different power combinations such as +12D, +16D, +20D and +26D and can be customised for other power requirements depending on patient’s requirement and extent of vision loss.

As compared to conventional spherical glass-based lenses, these aspheric LVAs are lighter by 60 per cent and much more powerful, offering better optical performance in terms of reduced aberrations and higher image quality.

“These lens are like using a magnifying glass by people whose vision is extremely low,” a scientist at the CSIO said. “However, conventional lens of such power would be extremely large and bulky and using LVA would specially be convenient for children,” he added.

The LVAs were launched at a function chaired by the President of India, Draupdi Murmu, during the National Awards for Empowering Divyangjans - 2024 held in New Delhi on Tuesday, a spokesperson for the CSIO said.

Scientists associated with the project said that the FLV was defined as impaired visual function that persists despite treatment or refractive correction. It can also be described as a visual acuity of less than 6/18 or a visual field less than 10 degrees from fixation. According to estimates, the prevalence of FLV in India is estimated to be 1.05 per cent, which means roughly 1.4 crore people are affected by this disability.

These LVAs have been fabricated using single-point diamond turning process, which is an ultra-precision machining technique used for fabrication of aspheric lenses. The user trials of these developed prototypes were carried out in collaboration with Artificial Limbs Manufacturing Corporation of India, Kanpur, and the National Institute for the Empowerment of Persons with Visual Disabilities, Dehradun.

Plans have been drawn to scale up the manufacturing of these LVAs using molding techniques that will enable rapid production and faster deployment among the affected population. The pricing for these lens is also being worked out.