CarpeDiem,
I had a look at the above link and out of professional interest (I am an optometrist) and I will ry to compare it to the UK standard.
To quote from one of our professional bodies information sheets (which can be found at http://www.assoc-optometrists.org/up...02-drivers.pdf):
The problem with the above is that it is all very vague (what precisely is good light, is the number plate clean or dirty, what type face is to be used,...) but it is what we have to work on.quote:
The standard for Ordinary drivers is the ability to read in good light (with the aid of glasses or contact lenses, if
worn) a registration mark fixed to a motor vehicle and containing letters and figures 79.4 millimetres (31/8 inches
high) at a distance of 20.5 metres (67 feet), or 12.3 metres (40 feet) in the case of an applicant for a licence for
authority to drive vehicle confined to Group K (milk floats and pedestrian controlled mowing machines). NB the
distance for the number plates introduced on 1st September 2001 is 20 metres, but at the time of writing legislation
has not been introduced to reflect this change, and “old style” number plates are to be used until the Act is
changed.
There is no precise Snellen equivalent to the number plate standard. Drasdo and Haggerty found that applying a
standard of 6/9-2 (6/10) resulted in a mathematical equivalent to this (i.e. this standard failed the same
proportion of people, but not necessarily the same individuals). The normal number plate test found on many
test charts is NOT equivalent and should not be relied upon. It must be emphasised that the statutory standard
of visual acuity for drivers is the practical test which has to be taken in good light. The number plate test is
prescribed in the Motor Vehicles (Driving Licences) Regulations and the Road Traffic Act 1988, makes it an
offence for anyone to drive a motor vehicle on a road while his eyesight is such (whether through a defect which
cannot be or one which is not for the time being sufficiently corrected) that he cannot comply with the standard
quoted above.
The Florida standard is at least a little more scientific. There is a difference in the Snellen figures used as the Americans are empirical and the UK is metric. So 6/6 = 20/20 (the first number is the measuring distance 6 metres or 20 feet the second number is the size of the letter being used, the larger the number the bigger the letter). 6/6 or 20/20 is taken as being "normal vision", but don't get me started on that one!
Anyway the web link above makes the three following statements of requirements:
So the first line equates to 6/12 (or better) vision in each and both eyes.quote:
Have 20/40 (or better) vision in each and both eyes. With or without corrective lenses.
If you have 20/200 (or worse) vision in one eye, you must have 20/40 (or better) vision in the other eye. With or without corrective lenses.
If you have 20/70 (or better) vision in either eye separately, or in both eyes together. The worst eye must have a vision screening better than 20/200. With or without corrective lenses. Referral to an eye doctor may be required.
Second line 6/60 (or worse) is usually the first single big letter at the top of the letter chart used in an eye test, then you must have 6/12 or better in the other eye. This seems a little at odds with the first statement, which says you have to have 6/12 or better in both eyes. But it seems from this statement that you have to at least have one eye that can read 6/12 or better.
However the third line says that as long as with both eyes together you can see 6/21 or better then as long as the weakest eye
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Now it just looks daft that I also replied
.
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