Watching television closely, contrary to what you might think, does not harm your eyesight. However, it can strain the eyes, so it would be advisable to keep an adequate distance from the screen. Obviously the distance must be proportional to its size: the bigger it is, the more you have to move away. Furthermore, children should not watch TV for more than 2 hours a day and it is important that right amount of lighting is provided, characterized by diffused and uniform light.
WHY DOES IT NOT DAMAGE?
The reason why the TV screen does not damage your eyesight as you might think is that it does emit radiation, but in limited quantities, therefore they are not dangerous for the eyes.
As for the right lighting, however, it is important because it can reduce visual effort and, in the absence of reflections, the eye is able to relax. Consequently there is an improvement in the perception of the details of the image and color.
WHAT HAPPENS IF YOU HAVE A VISUAL DEFECT AND WATCH WITHOUT LENSES?
Generally there is no deterioration of vision but it is strongly discouraged to do so because the eye would be subjected to excessive effort and therefore it would stimulate the appearance of annoying symptoms such as visual fatigue, burning, abundant tearing, headache.
SO WHAT DISTANCE IS BEST?
The distance is measured by the length in centimeters of the diagonal measurement of the screen multiplied by five. For example, a TV with a diagonal measurement of about 80 centimeters should be viewed at a distance of at least 0.8 × 5 = 4 meters.
As for high definition (HD) screens, however, the calculation is more complex.
For a Full HD the diagonal measurement of the screen is multiplied by 1.5 while for the HD the diagonal measurement is multiplied by 2.3.
IS THE TYPE OF SCREEN IMPORTANT?
Yes, with the most modern LED screens, the images are more stable and defined, therefore they make the eyes strain less, especially in case of prolonged stay in front of the TV. A doubt has spread regarding the potential harm of the blue light emitted by the LEDs to the retina, and therefore glasses with special filters for blue light have been put on the market. These perform a restful action for the eyes.