Redness of the eye can be caused due to various reasons, which are - lack of proper sleep, prolonged exposure to computer/laptop, watching television for a long duration, eye infection and so on. In order to prevent it we may have to use some eye drop in consultation with the doctor. Also, taking break from working (using a computer) and doing eye exercise can help correct this condition.
Most probably redness of your eyes is due to prolonged exposure to the computer screen. We normally do not realize it, but when we sit for long stretches on the computer working, we forget to blink and this causes dryness and severe strain on eyes causing them to to turn red. So make sure that you look away from the screen every 15 minutes and do palming exercises and blink your eyes for a few seconds continuously. Also, make sure to drink water frequently as the drying of eyes may also lead to severe itching after some time causing other infections. So staying hydrated is also necessary.
Eye redness can be due to some allergies, infections or may be due to inadequate sleep.
Have adequate sleep, get rid of exposure to allergic substances and wash face as soon as reaching home from outside. If it persists beyond this you may require antibiotic drops.