Dear Nicola,

Thank you for your e-mail.

Diagnosis of eye disorder by e-mail is fundamentally irresponsible.

I can do nothing more than to give you hints to help YOU decide 
whether you should seek local medical help.

1) "Conjunctivitis" is inflammation of the thin, elastic tissue surrounding
the cornea, i.e. surrounding the clear part of the eye. 
a) Conjunctivitis NEVER CAUSES PAIN.
b) Conjunctivitis is often allergic, caused by irritants inadvertently
   rubbed into the eye with the fingers.
c) Conjunctivitis is often the result of i) viral or ii) bacterial infection,
   in which case it is usually (but not always) self-limited and goes away
   like a "cold".
d) Conjunctivitis often causes irritation and foreign body sensation WHICH
   MUST BE DISTINGUISHED FROM PAIN
e) Conjunctivitis often affects both eyes at the same time.
f) Conjunctivitis often causes a mucous (slimy) or purulent (pussy) 
   discharge, which transiently blurs vision, causing BLURRING WHICH 
   TEMPORARILY DISAPPEARS ON BLINKING (or on washing the eye with STERILE water)

2) If an eye is a) painful or b) sensitive to light, it is afflicted not (only)
   with conjunctivitis, and should be examined by an ophthalmologist:
a) for possible elevated pressure (glaucoma)
b) for possible corneal ulcer or foreign body
c) for possible inflammation inside the eye;
all of which might cause irreversible damage to the eye.

3) If your eye problem does not subside and if your eyes are not examined
by an ophthalmologist, you should telephone me ANY TIME, day or night
at 617-548-5768, mindful that I might not get to the phone on time and
that you might need to make several consecutive attempts to reach me.

Jochen