MIT Inventor's Eye Scanner Now Used 40 Million Times a Year

If you've ever had your eyes checked with a quick, painless scan instead of a blinding flash, you can thank David Huang for making your appointment a whole lot easier.

The MIT engineer invented optical coherence tomography (OCT) in 1991, and it's now the gold standard for eye imaging worldwide. The technology produces detailed 3D pictures of the inside of your eye using barely visible infrared light instead of harsh camera flashes.

Huang didn't set out to revolutionize eye care when he started studying electrical engineering at MIT. He just wanted to combine his love of engineering with medicine, inspired by his father who worked as a family doctor.

The breakthrough came during his MD-PhD studies when his professor asked him to improve how doctors measure the thickness of the cornea and retina. Huang thought a technique called interferometry, which measures how light bounces off tissue at incredibly precise speeds, might work better than existing methods.

His hunch paid off spectacularly. The technology could detect tiny internal structures in the retina that other imaging methods completely missed.

Huang teamed up with his professor James Fujimoto and engineer Eric Swanson to build the first OCT machine. They tested it on tissue samples from Harvard Medical School and found it worked beautifully on both retinas and coronary arteries.

Their 1991 paper in Science introduced OCT as a completely new way to see inside the body. Today, doctors use it in 40 million procedures annually to diagnose everything from macular degeneration to glaucoma.

The Ripple Effect

Huang's invention earned him and his team spots in the National Inventors Hall of Fame in 2025, plus the prestigious Lasker Award and National Medal of Technology and Innovation in 2023. But the real impact shows up in doctors' offices every day.

The technology continues to evolve under Huang's guidance at Oregon Health and Science University's Casey Eye Institute. He's now developing OCT angiography to image blood flow in tiny capillaries and OCT optoretinography to map how individual light-sensing cells in the retina respond.

He also sees patients, conducts research, and cofounded GoCheck Kids, a digital platform that makes eye screening easier for children.

Huang credits his success to standing at the intersection of engineering and medicine. Pure engineers might not recognize medical problems that need solving, and doctors might not know the latest technology could help.

Sometimes the best inventions come from people who speak two languages: the language of science and the language of healing.