This set consists of our Vertex Distance Gauge and Conversion Disc supplied in a practical wallet. This useful set resulted from cooperation between Moorfields Hospital and Sussex Vision. The Gauge is used to measure the distance between the cornea and the spectacle lens simply and easily. The rotary Conversion Disc allows calculation of the equivalent effective power at alternative distances between the cornea and the lens. This is particularly useful to show the power differences caused by trial lens and spectacle lens distance. It is essential to have the means of assessing the power compensation required for corrections over 5 dioptres. 

The Conversion Disc (SGR-271-VCD) and the Vertex Distance Gauge (SGR-271-VDG) may be ordered separately.