For information - and I only add this to illustrate the 'risk assessment' approach- in my case, there is no correction for my diplopia. I tried prisms etc but nil will help - so no glasses etc to take away. I patch when I drive obviously but that doesn't affect my mobility cos I could get around other ways in a day to day way. I need the patch to do my job because its a regional role but DDA doesn't ask us to look at that element only day to day mobility.

I share that personal health info only to try to explain the complication when the usual test/risk assess approach is used in some DDA cases. Hard for us sometimes when that is the fundamental basis of so much of what we do.

Jane. PS thanks for those who provided off-list comments, further reading etc