Yes, I also agree with what your father has told you. So you'd better not watch too much TV or be sitting in front of the computer for a long time. They do damage you eyes. Let's talk about the reasons. According to the experts, watching the television or the computer is enough exposure of the eyes to a constant light source. In this way, Strong light from them can cause serious damage not only to the cornea, but also to the lenses. At this moment, just like you feel, it can just like there is sand in the eyes and it will also lead to constant pain when eyes encounter some light of particular wave lengths. Besides, when too much light goes into your eyes, especially for a long time, it will increase the eye strain and then can lead to many other eye diseases. So just don't watch tv or computer in a long time. And also, you should control the distance between you and the machine.
This is an easy question, firstly you gotta be aware of that elder people have poor vision, thus, they have to see both distant things and near things. Therefore, bifocal glasses became the best and most convenient solution to their problem. With bifocal glasses, they are able to see things clearly in near and far distance..
For bifocal glasses, there are two different optical powers. We know, therefore, bifocal glasses can be used by those crowds who have hyperopia and myopia. Usually, people are needed to wear bifocal glasses over 40 years old. At the same time, the bifocal glasses, in the early time can relieve eye fatigue. So, there is no wonder that most of people recommend bifocal eyeglasses to older people.
When people get older, they may get the most possibility of presbyopia. That is to say, they may need to wear the presbyopia glasses to watch near things, such as reading newspapers, watching TV and other things. However, when they see far away things, they may feel a little flurry. And the bifocal glasses are designed into two parts. The main lenses of it are to see the far place and the down part adopts the presbyopia lenses. Using the bifocal glasses saves the energy for the older people to change the glasses to see the near things.
Bifocal glasses is a kind of glasses that have two focus, one helps wearer see distance while the other helps wear see closer objects such as reading book. So, those glasses are often applied for people who suffer two vision problems such as presbyopia and myopia. This is the reason why bifocal glasses are often applied for older people (usually over 40 years old).
The bifocal lenses are always used by older people who are suffered myopia and presbyopic. This kind of lenses has two focuses. One is used to adjust the prescription, and another is used to correct the presbyopic. On the lenses, there is a divided line. Watching from the upper of lenses is a far distance, and watching from button is in a short distance. In result, those glasses are recommended to the people who are more than 40 years old and suffered with myopia and presbyopic.