The device, which has been dubbed the ‘simultaneous vision simulator’ or SimVis, is designed to help cataract patients choose between the different artificial lens types that are available to th. These lenses are surgically implanted in the eye to replace the patients’ own lenses, which have become cloudy, hindering vision.Mr Carlos Dorronsoro, one of the researchers, said, Currently, the decision on which intraocular lens (IOL) is implanted during cataract surgery is typically based on the explanations and experience of the surgeon. But it is difficult for patients to imagine the new visual experience provided by some of these lenses, therefore, it is very difficult to make the decision. The researchers asked nine volunteers to use the SimVis to compare seven different lenses providing monofocal, bifocal or trifocal corrections while looking at a poster of a landscape, a laptop, a tablet, and a smartphone, with high contrast text and eye charts placed at different distances. Based on the lens simulations, the testers indicated clear preferences for certain corrections. The favoured or rejected lenses were different for different testers, suggesting the need for this kind of simulation prior to surgery to customise the selection of lenses according to patient requirents, Mr Dorronsoro stated. Clinical use of the SimVis could provide an evidence-based way to assess the subjective needs and preferences of patients before they undergo cataract surgery. The researchers are also working on a smaller binocular version of the SimVis to simulate different lenses in each eye, and are aiming to have this version approved for commercial sale by 2017.