Large pupils do not automatically rule out laser eye surgery, but they increase the risk of night-time halos and glare, so planning needs extra care.
How pupil size affects vision
In low light, large pupils expose more of the peripheral cornea, where optical quality may be lower, especially after high or wide ablations.
- Scotopic pupil measurements are taken as part of pre-operative work-up
- Large pupils relative to treatment zone can increase halos and starbursts
- Higher prescriptions often require larger optical zones to minimise symptoms
- Surface quality and residual aberrations become more important
- Night driving demands should be discussed in detail
Ways to manage large pupils
Techniques in planning and counselling aim to balance spectacle freedom with acceptable night vision.
- Choosing larger optical and blend zones where corneal size allows
- Preferring procedures that induce fewer higher-order aberrations
- Setting realistic expectations about possible halos, particularly early on
- Considering monofocal lens or ICL options in selected cases
- Using anti-glare coatings or glasses at night if symptoms persist
