Mrs SN, a 76 year old underwent routine left cataract surgery for moderate nucleo-sclerotic cataract. Pre-operative corrected acuity was 6/9. At the 2 week post-operative visit, acuity in the same eye was 6/12. The eye is white, cornea clear, anterior chamber quiet, intra-ocular lens well positioned within the bag, fundus examination is normal. A routine post-operative macular optical coherence tomography (OCT) shows a normal retina profile with no cystoid macula oedema. Pachymetry reveals a central corneal thickness of 578 microns in the operated eye compared to 533 microns in the contra-lateral eye.