Have you cleaned them properly ?
Maybe your eyes are just irritated. Either that
OR
Your eyes may be dry from the contact lenses suffocating your pupil.
ROFL suffocating ur pupil.....thats wrong=P ur pupil is the aperture in your eye, so it doesnt need nutrients. its the other eye structures [sclera/conjunctiva/iris etc] that do...
possibly that after not wearing ur contacts for ages they could be dirty as stuff could build up in your contact lens solution...OR, if previously u wore contacts without giving ur eyes rest before, they can become super dry...so when u next wear contacts they cant tolerate being dry for as long and will hence redden faster...
try to use oxygen permeable contacts. theyr better=]