Great idea bomber!
Island Air please remember that every couple of quid counts for some of us. Also, bomber's chart can be produced quickly at home over the Christmas Hols.
I made similar charts up a few years ago (using Word Perfect so details slightly different) and they have proved extremely useful.
Some extra important information:
Visual acuity increases considerably with illumination of the chart up to about 500 Lux (lumens per square metre) and this is fairly bright. As a guide, two 60 watt brand-new light bulbs about 1/3 metre in front of the chart would achieve about 500 lux. The direct glare from the bulbs must obviously be screened from the observer for the measurement of acuity. Alternatively, a single 100 watt reflector bulb (new) about 1 1/2 metre away will produce similar illumination.
The illumination is supposed to be even and without specular reflections.
My experience of eyesight standard tests is that the siting of the chart and the illumination is often very substandard. In my opinion, the medics often don't understand much about the importance of maintaining an illumination of at least 500 lux before trying to measure acuity.
I have been asked to read a test chart by a UK AME which was not illuminated except by ambient room lighting! He did not seem to be aware of the illumination standard required and eventually pointed an anglepoise light at the chart, after which I passed. Don't accept defeat unless the chart is correctly illuminated.
If anyone is interested (or cares) the standard for an internally illuminated chart is a luminance of 140 candela per square metre.
Happy Christmas to all