"I was so afraid they would get lost or hurt," she said. "But I found they really cherished the chance to travel and they were so disciplined."

To ensure the safety and smooth operation of the tours, Cai has made some rules: a partially blind person must pair with a completely blind one, and no one should be left alone under any circumstances.

When traveling outside Chongqing, she takes only about 10 people with her to ensure she can look after them properly.

She usually brings two whistles to send signals to her teammates during the trips. At some crowded scenic spots, if other guides use one type of whistle, Cai will use another to differentiate her sound.

To save on costs, Cai spends a great deal of time searching for cheap transportation, accommodations and dining options.

It took her about three years to prepare for a trip to Xiamen, a coastal city in Fujian province. In March 2015, she finally made the trip with 13 team members.

"When I touched the trees, felt the ancient streets under my feet, heard the ocean waves, felt the wind from the mountains and heard birds singing in the forest, I seemed to really 'see' nature's beauty," said Zhang Hong, who has participated in many tours organized by Cai.

They like to ask others to take photos for them so that they can show them to their family and friends.

Cai's special travel group has attracted much attention from the public and often receives generous help from warmhearted tourists, train and flight attendants, as well as restaurant and hotel management. In recent years, a local travel agency welcomed them to join its tours at home and abroad.

"We have received so much help from others," she said. "We want to give back to society as well."

Cai has set up a volunteer team with her visually impaired friends called Light of Love. During their trips and when they have spare time, they often provide free massage services and mini concerts.

"Some of my team members are very talented musicians. Some can write songs and others have very good singing voices," she said.

For Cai and her teammates, travel has a special meaning.

"We derive confidence and dignity from our journeys," she said.

"When we come back, we can carry on with more courage."

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