It could be an allergy, but I need to ask you few
questions.
Are you female and wear some eye make up? (if yes, the you should
remove it properly, with something what is made for sensitive and
allergic eyes)
What kind of pillow, bed sheets and blanket do you use?
Do your eyes also itch, or burn or get red,(red especially in the
inner corner)?
Now about the breathlessness. How often does it happen? Does it is
happen throughout the whole year or only in some months or periods
of the year?
Are you concentrated on something else when it happens or are you
resting or what else are you doing when sitting down and it
happens?