During the day, the pupil
is smaller and it is easier for the eye
to compensate for inaccuracy of the prescription of your contacts. This is called the pin hole effect. At night, the pupil is big and there is no pin hole with resultant poor vision
. Others have poor vision because of aberrations on the peripheral cornea which become more significant as the pupil gets bigger. Custom wavefront laser vision correction
may be of use to treat the peripheral irregularities.