MERoV: the Monofocal Extended Range of Vision Study

About The MERoV Study

Summary: Generally single focus lenses will either give good distance or near vision (whichever the patient prefers) without any glasses. However, small proportions of patients who have had cataract surgery with simple single focus lens can not only see well for distance but can also read without glasses. In the literature several factors have been identified to contribute to this phenomenon such as residual short sightedness (myopia), the shape of the cornea (astigmatism), the size of the pupil and irregularities (aberrations) within the optics of the eye (in the cornea and lens).

We are proposing this research project to:

1. Screen a set of patients after normal cataract surgery with a single focus lens aimed at good distance vision at 3 months after surgery to identify patients who are able to see and read well without glasses.
2. Identify the combination of factors responsible for this phenomenon in the patients who are achieving this.

Patient’s with healthy eyes apart from cataracts will be invited to take part in this study. At 3 months after surgery they will have their un-corrected vision checked. They will also have their reading speed assessed without any glasses. They will undergo a through refractive check by an optometrist to assess the power of the spectacles (if needed) and following this they will have a scan of the eye (a technique known as wave front analysis which uses very sophisticated optics) to capture the optical distortions in the structures of the eye.

If this study is able identify factor/s responsible for giving good unaided reading and distance vision then this factor can be reproduced in eyes undergoing cataract surgery. This will mean that the patients can have an increased option of spectacle independence without the need for expensive multifocal IOLs and their associated side effects such as glare and halos, particularly at night.