Cataracts are a medical condition in which proteins in the eye begin to clump up around the lens and distort vision. If left untreated, they cause blindness. However, despite being completely curable, cataracts have still caused an estimated 20 million cases of blindness throughout the world.

In individuals suffering from cataracts, eyesight can be restored by removing the clouded lens. In the latest TedEd video, we learn the extensive history of how we have attempted to do this. Some practices, such as couching, which involves chipping away the lens using a sharp object, are grotesque and horrific. Others, such as modern cataract surgery, which replaces the clouded lens with a clear artificial one, are relatively easy and safe. Still, despite these advances in cataract removal, the condition continues to blind millions. According to the TedEd video, the main reason for this is limited access to health care, poor infrastructure, and a shortage of doctors who are capable of completing this delicate operation. In addition, in many rural areas throughout the world, individuals do not seek treatment for their cataracts because blindness is seen as an inevitable part of aging.

Despite these setbacks, there have also been major strides in treating cataracts on a global scale. For example, some hospitals, such as Aravind Eye Hospital in India have made the life-changing operations significantly more affordable. Researchers in California are also working on developing a solution that, when dispensed as eye drops, would be able to “melt” cataracts away. In addition, increased community awareness use of mobile phones now means more individuals in rural areas are now getting more access to these truly life-changing treatments.