A primary school in Wuhan has used new desks and chairs to prevent students from getting short sight. The desks and chairs make students have the correct posture, especially when reading and writing. Each desk has an adjustable steel bar. The bar can help students keep their eyes at least 30cm from books. Zhang Jianming is headmaster of the primary school. She said the new desks and chairs were provided by an eye care centre in the city. The school carried out a survey last September. It showed that about 7 percent of its 1,093 students said they suffered from short sight. The new desks and chairs have already improved the students' posture, but both teachers and students might need more time to get used to them. Yang Lihua is head of the Wuhan Youth Eye Care Center. She said the desks and chairs were introduced to 19 schools on a trial basis. "During our research into short sight, we noticed that the number of students with short sight was increasing. This is because parents are teaching their children to read and write at a very early age without paying enough attention to their posture," she said. Feng Junying is a doctor at Beijing Jingshan School. "I think the new desks and chairs in Wuhan will certainly be helpful," she said. "But bad reading habits at school are not the only reason for short sight. Children are using mobile phones and iPads when they are very young. This can be another reason for short sight at a young age." From the passage, a good way to protect our eyesight is to  _  .
buy an adjustable steel bar go to the Youth Eye Care Centre often have a correct posture when we are studying read less and use mobile phones and iPads less