Hi Yhuing
Painful red eyes can have a number of different possible causes, and it's best if you go and see a doctor to find out what is the cause, as well as to get some treatment for it.
As regards the risk of spread or transmission, that is possible if the red eye is caused by an infection such as 'conjunctivitis'. Usually conjunctivitis also causes a lot of discharge and sticky eyes, especially in the morning after waking up.
If you do have these symptoms ie red eye plus sticky discharge, you should take 2 main precautions to avoid spread:
1. Wash your hands as soon as possible after touching your eyes (whether to wipe them or instill eyedrops etc)
2. Tell the other people around you NOT to touch their eyes
Conjunctivitis is not spread by staring or looking at red eyes.
Luckily for that, otherwise people like me would be getting red eyes all the time!:)
Finally, just to re-emphasise, red eyes could have a number of different causes and we cannot tell exactly what it is without examining you. You might have something other than conjunctivitis.
Therefore you should go see a doctor to get an examination and diagnosis, and then some treatment for the red eye. I wish you a speedy recovery.
