Enlarged Pupil

After 2 surgeries (macular hole 7 months ago and retinal detachment 5
months ago) my pupil in the affected eye remained permanently
enlarged. I have not used any eye drops (except tears occassionally)
in 4 months, and I presume it will remain this way. Is this "normal",
considering the situuation? What causes it? And what's the effect of
a larger pupil on vision? I am scheduled to a cataract surgery (same
eye) later this month.