Sankara Nethralaya, which pioneered the scientific self-testing visual acuity chart in Tamil, is now set to take the tool to various places across the State. The Tamil log MAR (logarithmic minimal angle resolution) chart was put together by a team at Nethralaya’s Elite School of Optometry (ESO) after rigorous testing of typeface, size progression, size range, number of words per row and their spacing.
Currently, ESO has put up the charts at two vantage spots in Chennai — a temple in Ashok Nagar and the bustling Jeeva park in T Nagar.
“We propose to seek support from NGOs to instal more charts in several places across the State. This will help us reach out to more people and encourage a culture of regularly testing one’s vision,” said N. Anuradha, faculty member and vision screening coordinator, ESO.
The ESO’s research arm, Sundari Subramanian Department of Visual Psychophysics, which executed the project and finalised the optotypes for the Tamil chart has also prepared Kannada and Bengali versions though these have not yet been released for public benefit in Bangalore or Kolkata where Nethralaya has full-fledged branches.
These charts seek to address the unmet need for vision testing in regional languages, says Ms. Anuradha. The Tamil log MAR charts — which stand up much better to research scrutiny than the conventional Snellen chart popular in clinical practice — are ideal for deployment as a mass vision screening tool in rural areas, she said.
According to ophthalmologists, uncorrected refractive error is a major cause of vision impairment, and the second most common cause of blindness. In 2007, India had an estimated 456 million people who required vision correction (spectacles, contact lenses or surgery) to be able to see properly. This included 37 million children younger than 16 years of age.
Ophthalmologists believe that these visually impaired sections would have regained normal vision if they had timely access to an eye examination and spectacles.
However, lack of access left 133 million of them, including 11 million children, blind or visually impaired due to uncorrected refractive error.
ESO’s research wing also developed the Pocket Vision Screener (PVS), a condensed log MAR screener available in a combination of English and Tamil alphabets.
According to Ms. Anuradha, the pocket screener is very handy for use in schools or community screening initiatives if the population to be tested is huge.
Apart from being portable and relatively cost-effective, the simplicity of the chart makes it easy to use for teachers and students. In fact, ESO uses the tool to mobilise vision ambassadors who can assist the clinic during mass screening sessions.
Also, since this is a “pass or fail” kind of a screening test, a large number of people can be screened within a short time. It can also be distributed to the public as a self-screening aid for ocular problems before deciding on consulting an eye-care practitioner, optometrists said.