It's time for the second season of CGTN's original series Tech It Out. On Global Watch this week, we are showing you the scientific and techonological breakthoughs in China that will reshape our world. Like all developing countries, China is facing a huge gap between public health needs and the number of doctors. In today's Tech It Out, we will find how technology can help fill that gap.

GUEST PROF. WU QIANG OPHTHALMOLOGY DEPARTMENT THE 6TH PEOPLE'S HOSPITAL OF SHANGHAI "We may observe the eye's fundus blood vessel and the nerve directly through instruments. We can use a photo of the fundus to tell us if there are pathological changes going on in a person's whole body, such as with diabetes."

Over 100 million people across China live with diabetes. One of its major complications is diabetic retinopathy, or DR; a leading cause of blindness. It gradually blocks one's vision before eventually taking it away forever.

PROF. WU QIANG OPHTHALMOLOGY DEPARTMENT THE 6TH PEOPLE'S HOSPITAL OF SHANGHAI "The progression of more than 90 percent of patients' diseases can be blocked if we can start treatment at an early stage."

Despite early intervention proving effective, carrying it out in China is another story.

PROF. WU QIANG OPHTHALMOLOGY DEPARTMENT THE 6TH PEOPLE'S HOSPITAL OF SHANGHAI "Now, national statistics tells us we have 30,000 eye doctors. All of these are concentrated in big cities. It is not enough to serve such a large group of patients with such a small number of doctors."

Now doctors see an even easier ophthalmic future, one powered by artificial intelligence.

The human brain and eyes are masterpieces of evolution. The brain makes sense of what our eyes show us. You can effortlessly tell a pattern like this. That's the number 9. But for a computer, it suddenly becomes extremely difficult.

PROF. SHENG BIN COMPUTER SCIENCE DEPARTMENT SHANGHAI JIAO TONG UNIVERSITY "When our brain tries to identify the number 9, it instantly helps us to eliminate a lot of the distractions. But when we try to write those rules down and expressed them algorithmically, we find it a difficult task to accomplish."

To SEE like a human, the machine needs to FUNCTION like the human brain. Scientists now use a new type of algorithm called a neural network to mimic the brain.

PROF. SHENG BIN COMPUTER SCIENCE DEPARTMENT SHANGHAI JIAO TONG UNIVERSITY "To be more specific, we set up an input layer, an output layer, and a number of hidden layers. When we have a new image input into our neural network, like from the discharge of our neural cells, information will be sent layer by layer to our output layer, and finally, we get the results of we're supposed to have."

To recognize a hand written figure, like the digit "9", the network will first divide the image into pixels and put them into the first layer starting process. Each layer in this network specializes in extracting specific features. First few layers break down the images into larger chunks of patterns. A "9" is made up with a loop on the top and a vertical line on the bottom right. The next layers look for some lower-level feature-smaller edges and corners that make up those patterns. As the recognition process breaks down into more subproblems, the network captures more features that help convince it that this image is nothing other than the digit 9.

PROF. SHENG BIN COMPUTER SCIENCE DEPARTMENT SHANGHAI JIAO TONG UNIVERSITY "At the beginning, our neural networks, like our baby's brains, had no reserve of knowledge. We have to constantly feed them with some of the training data. By increasing the amount of data, we will make our network more and more accurate."

It may seem meaningless to have a machine recognize digits. But what if that machine can be trained to read retinal images and detect the early risks of diabetes? Experts say the excitement over neural networks comes from only needing to show it retinal images with diabetic retinopathy. It will find the features and slowly create a sort of "special intuition" to similar images.

PROF. WU QIANG OPHTHALMOLOGY DEPARTMENT THE 6TH PEOPLE'S HOSPITAL OF SHANGHAI "We will go to another group of patients to test whether it can fully identify their diseases. This is for ensuring our accuracy."

However, a neural network trained this way can only tell if you have the disease, but it can't explain its diagnosis. The machine can also be shown images with distinctive spots or bleeding circled by human doctors, and it can then learn to recognize the sign of disease.

A well-trained AI device will be loaded onto portable equipment or even a handset, to be deployed in more clinics around China. As machines started seeing more retinas, scientists have found that it started seeing things people didn't know were possible: things that have nothing to do with your eyes.

PROF. SHENG BIN COMPUTER SCIENCE DEPARTMENT SHANGHAI JIAO TONG UNIVERSITY "And what's interesting is that our neural network, by looking at the fundus images, can identify other diseases, like diabetes, kidney disease, diabetes hypertension, and age, which is beyond the reach of an ordinary human physician. Because he or she has not been trained in this kind of knowledge, and this is a new kind of knowledge."

PROF. SHENG BIN COMPUTER SCIENCE DEPARTMENT SHANGHAI JIAO TONG UNIVERSITY "Some of the knowledge we acquire can be summed up through books, but much knowledge is actually hidden in the depths of the brain and can only be interpreted as unconscious experiences. Our machine learning can solidify and record these hidden experiences in our model at the same time, which gives it a very strong expressive power."

PROF. WU QIANG OPHTHALMOLOGY DEPARTMENT THE 6TH PEOPLE'S HOSPITAL OF SHANGHAI "In the far rural areas, we can use this remote treatment to follow-up on early disease diagnosis and preventive care, especially for those diseases with a high incidence rate. So this will actually be good for the whole society, good for the whole human race."