Del Mar thinks that research in primary care is a lost cause1: not so.

One of us (JGH) instituted a glaucoma screening programme in a four partner general practice during 1991-4 using basic equipment (Snellen’s chart with and without a pinhole, ophthalmoscope, Perkins’ tonometer for intraocular pressure, and oculokinetic perimetry charts for visual fields). An additional hope was that screening with these methods might be applied in the developing world, where glaucoma is more prevalent and batteries may be the only energy …