For anyone who is finding themselves losing track of time when in front of the computer why not try the Healthy Browsing extension.

This provides reminders to drink water, blink, correct your posture and stretch for a healthier browsing.

When browsing, we often forget to blink as often as our eyes need it.  We forget to drink water and we also sit ina fixed and wrong position.  This extension notifies you to blink, drink water, correct your posture and stretch.

If you use the computer for the entire day and follow the reminders, you will feel your eyes less tired, you will be better hydrated and you won't feel any numbness.

Recommended settings:

Drink reminder: 45 minutes
Blink reminder: 20 minutes
Stretch reminder: 90 minutes
Posture reminder: 20 minutes

Link: Healthy Browsing Extension