Your essay is really good, but I think you should you a wide range of words.
Tend=> have propensity to do something./for something.
In the age of technology, people tend to sit on the sofa watching television and using the computers instead of taking part in outdoor activities. While I agree that this trend can lead to some diseases in people, I believe there are some other reasons that negatively affects affect their health.
On the one hand, the introduction of computer and television truly has negative impacts on people's well-being. Since electronic things ( should use gadgets) appeared, people's home life has become so convenient and interesting that they tend to (have propensity to) spend most of their time staying at home. People would gradually prefer watch a favourite program or play an appealing computer games rather than go going out for a walk or play a sport. This leads to an inactive lifestyle (sedentary lifestyle) and can cause a lot of diseases. For example, spending too much time staring at the screen of the television may result in some eye-related diseases, especially in children who are becoming too exposed to technology.In addtion,light blue from eclectronic devices not only harms our eyes but also affects the quality of our sleep. Moreover, some people may get obesity if they sit in one certain position for too long without doing physical exercises.
On the other hand, electronic devices are not the only causes of people's negative health conditions. Other bad habits can also contribute to people's getting diseasesmental and physical illnesses.For example, those who consume too much fast food without doing exercise will possibly get down to obesity. Furthermore, those who study for too long without enough light may also be involved in eye-related diseases such as myopia, known as short-sightedness.
To sum up, I agree that with the inventions of eletronic devices, people's health has been negatively affected (adversely impacted) by avoiding them themselves from physical activities. However, there are still other bad habits which are not related to technology but can damage people's well-being. People should be aware of this problem and moderated moderate their lifestyle to stay in good health.