For decades, millions of Indians have suffered blindness that could have been avoided.

Cataracts, which cause the eye’s natural lens to become cloudy, are the leading cause of the condition around the world, and they account for around 62% of the cases in India. But this can be prevented by surgically replacing the natural lens with an artifical one (known as an intraocular lens).

It was the simplicity of this solution that prompted ophthalmologist Govindappa Venkataswamy to set up the Aravind Eye Hospital in Madurai, in the southern state of Tamil Nadu, in 1976. At a time when a staggering 13 million Indians (pdf) were blind, Venkataswamy saw an opportunity to supplement the government’s efforts to increase the availability of eye-care services, and potentially eradicate preventable blindness in Tamil Nadu.

“The only capital they had was their personal assets,” Soumitra Pandey, partner and Mumbai office head at The Bridgespan Group, a Boston-based non-profit, told Quartz. Despite the limited resources, their vision for eliminating what they called “needless blindness” was always grand, Pandey added.

Today, what started out as a single space with 11 beds is now a network of 11 hospitals in Tamil Nadu, which have helped cut the state’s rate of cataract blindness by half, according to a recent case study by The Bridgespan Group.

Every year, Aravind performs around 250,000 cataract surgeries, most of them for free or what the hospital chain refers to as “zero price,” in an attempt to treat every patient as a customer, regardless of their ability to pay. This variable pricing model, along with several cost-cutting innovations, has helped create a sustainable business that provides world class eye-care services at a fraction of the cost charged by hospitals in the west, the case study says.

In a country that is still home to a massive population of blind people—around 12 million, or one-third of the global count—Aravind’s success in Tamil Nadu has implications for the rest of India, besides the rest of the world. Here’s how the company is providing essential care to those who need it the most:

Affordability = accessibility

At the very first Aravind hospital, six out of the 11 beds were reserved for patients who could not afford to pay. Their surgeries were subsidised by the patients who could, and this remains the policy to this day. It works because doctors at Aravind are more productive than elsewhere, trained to perform as many as 2,000 surgeries a year, compared to the Indian average of 300, according to the study. This helps to offset the cost of free care, essential for the millions who wouldn’t otherwise be able to afford it.

Training and efficiency

The hospital chain has focused on efficiency. By using an assembly line system and meticulously planning the availability of operating equipment and support staff, Aravind has enabled its surgeons to quickly move from operating on one patient to the next, increasing the total number of procedures performed every day.

At the same time, it has not compromised on quality. “Aravind’s rate of complications is half that of the United Kingdom’s National Health Service,” the study says. (These high standards also work to attract patients who can afford to pay, which in turn helps the company subsidise treatment for the poor.)

Over the years, it has also developed its own manpower, Pandey explained, by training more surgeons who can perform specialised procedures and by providing opportunities to rural women in becoming mid-level ophthalmic professionals, helping prepare the patients for surgery.

Innovation

In the 1980s and 1990s, intraocular lenses were imported from the US, making them expensive and more or less out of reach for most patients. But in 1992, Aravind decided to create its own version and established the not-for-profit Aurolab to manufacture them. In doing so, the company was able to cut the cost per lens from $70 to just $2, significantly reducing the cost of surgeries, the case study says. Today, Aravind’s intraocular lenses are sold in 120 countries, and account for nearly 8% of global production.

By cutting costs in the operating room, increasing efficiency, and holding regular screening camps in rural areas, the hospital chain has managed to help reduce the incidence of cataract blindness in Tamil Nadu, a feat that desperately needs to be repeated at a national level.