The is an ideal lens for doctors who regularlycater to populations prone to glaucoma and other posterior pole abnormalities.The double aspheric design and field of view offered by a 78D offers clear andlarge views of the central mid-retinal regions. This lens offers a highmagnification without cutting down too drastically on the field of view.Thislens is a popular choice as a general diagnosis lens among doctors who prefer alarger ring size than the more common and smaller profile of the 90D. Dilationis required to obtain optimum retinal imaging with the 78D