Vision is very complex. The human eye takes in peripheral vision. It focuses near and far. It adjusts to changing light. It pictures shapes, contrast, color, and much more.

There are many ways for vision to be impaired. For example: Jeff Regan was born with optic nerves that did not grow correctly. Yvonne Felix lives with Stargardt disease. That disease causes vision to weaken at a young age. She was declared legally blind when she was 13. And there are many other conditions, diseases, or accidents that can cause people to lose much of their eyesight.

eSight developers estimate that there are nearly 300 million blind people in the world. About 200 million of those could be helped by their glasses. Why only 200 million? eSight can’t help with total blindness. It can enhance vision. It can’t create vision. It can help with some kinds of damaged vision but not others.

Here's what makes eSight promising. It can be adjusted differently for the vision needs of each user.

By February of this year, not many people used eSight glasses—only about 1,000. But that number could grow fast because eSight upgraded its product. It plans to make it more affordable too.

eSight Facts:

• A forward-facing video camera records the scene.

• The signal travels through a cable to a device. The device filters the image. The user can adjust it to improve contrast, zoom, color, focus, and more.

• The image plays on two thin video screens mounted inside the headset.

• Adjustable tilt allows users to wear glasses and use what vision they still have. They can walk around while still being able to view the headset screens.

• The headset tilts down for concentrated viewing such as reading.

• The headset includes a front light, microphone, and speakers. Users can stream content from their computer or phone right into the headset.