It will be bad for your eyesight by staring at a computer screen for a long time, and it will be good for you to relax your eyes by looking at something else far away for a while every a few minutes.
To do so, you can check out Protectyourvision as mentioned before. The following will show you another similar free web app — 20 Cubed, which is a Chrome extension for you to protect your eyes by having a rest every 20 minutes.
After installation, the extension will work automatically and start to countdown from 20 minutes, you can pause or reset the timer any time. When the time is up, there will be a pop-up window in the left top of your current visiting webpage, such as what you can see from the following screenshot:
The pop-up window will remind you to look at an object at least 20 meters away from the computer screen for 20 seconds. When time is up, the pop-up window will be closed and the extension will start to countdown from 20 minutes again.
By the way, there is no sound alert when time is up, which is fine for me, but if you like to be reminded by voice, you can check out Protectyourvision instead.
Related free web apps:
