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Flashcards in visual requirements for driving Deck (56)
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what is it a criminal offence for a driving licence holder or applicant to do

fail to notify the Drivers Medical Branch, Driver and Vehicle Licensing Centre, Swansea, immediately they become aware of any eyesight condition which is likely to cause them to be a source of danger to the public when driving

Failure to notify can also have serious motor insurance implications


by law when is awareness of a criminal offence normally regarded

regarded in law as starting as soon as the person has knowledge that a danger exists and this includes when they have received professional advice that their condition represents an immediate or potential danger when driving


what type of vehicles is group 1 drivers allowed to drive

ordinary family cars and light vans


what is the reading of number plate standards for group 1 drivers and what year of number plates does this refer to

- the ability to read in good daylight (with the aid of glasses or contact lenses, if worn) a registration mark fixed to a motor vehicle and containing:-
characters 79mm high and 50mm wide from 20 metres (just under 66 feet)

- this refers to a post 1st September 2001 number plate


what new addition was made to the rules of reading a number plate, from when did this rule apply and why

- In addition, the visual acuity (with the aid of glasses or contact lenses if worn) must be at least 6/12 (0.5 decimal) with both eyes open, or in the only eye if monocular.

- from May 2012

- Brings the UK more in line with the EU standard which is 6/12 (or 0.5 decimal which is the notation Europe tends to use instead of snellen)


what is there no precise snellen equivalent to and what implications can this have when testing

- to the number plate standard
- The normal number plate test found on many test charts is NOT equivalent and should not be relied upon


what did Latham et al (2014) find about the visual acuity standards related to group 1 drivers

- With a binocular VA of 6/12 not all participants could pass the number plate test (as artificial light in the test room is not the same as daylight)
- In addition, some participants passed the number plate test but had VA below 6/12 (approx. 14-15%)


what did the findings of Latham et al (2014) suggest in order to best predict drivers’ ability to read a number-plate

- vision should be assessed using a logMAR letter chart or a Snellen chart scored by full line (i.e. all 5 letters on every line of the LogMAR)

- Drivers with 6/7.5 (+0.10 logMAR) or better vision can be advised that they meet the driving standard. If no 6/7.5 line on the chart then driver should be able to read 6/6.

- Drivers with acuity between 6/9 and 6/12 (+0.12—+0.30 logMAR) should be advised to check their ability to read a number-plate, as some may not be able to.


what did the AOP advise about how optometrists should respond if a patient asks if they're fit to drive

- optometrists should not provide certificates of ability to pass the “number plate test” based on consulting room tests

- Statutory law and the law of tort make it unwise to advise on ability to pass “number plate test” based on Snellen VA alone

- If it is only acuity that is in question (i.e. not fields or diplopia etc) it is best to advise the patient to satisfy themselves that they can pass the “number plate test"

- If in doubt the patient should report to the Licensing Centre who will arrange for the test to be accurately carried out at a Driving Test Centre


what should a patient do if they're in doubt about whether they meet the visual requirements as a group 1 driver from their test results at the opticians

the patient should report to the Licensing Centre who will arrange for the test to be accurately carried out at a Driving Test Centre


if a patient's unaided vision is worse than 6/12, whose responsibility is it for the DVLA to know of this and what must the optometrist do on their side

- It is the patient’s responsibility to inform the DVLA if they are below the required visual standards for driving

- Explain that the patient’s insurance may be affected if they do not wear their glasses

- Annotate the record card with advice given to the patient


what must you as an optometrist do if a patient refuses to wear their distance glasses in order to meet the visual requirements for group 1 drivers and refuses to take your advice

- note this on the record card – ideally get patient to sign this

- If the patient is “…clearly visually dangerous”, and is continuing to drive despite your professional advice, consult the legal department of the AOP before going straight to the DVLA as this can breach patient confidentiality


which types of vehicles are group 2 licence holders allowed to drive

- LGV = large goods vehicles (lorries)

- PCV = passenger carrying vehicles (buses)
Must pass the number plate test


what 3 changes wee made from march 2013 in regards to group 2 licence holders and their visual requirements

- Must achieve at least 6/7.5 VA in the better eye [was 6/9 previously]

- Must achieve at least 6/60 VA in the worse eye [was 6/12 previously]

- Must have a corrective power of equal to or less than +8.00D (due to aberrations in high positive lenses) and there's no specific limit for the corrective power of contact lenses


why were more stringent va's for group 2 drivers required

as they have more responsibilities


why is the spectacle corrective power of no more than +8.00D for group 2 drivers required and what exceptions are there

due to the aberrations found in high +ve spectacle lenses

however they can use contact lenses that are > +8.00D in power


give 6 suggestions as to why the visual requirement rules for group 2 drivers does not help optometrists

- The difference in VA between 6/7.5 and 6/9 is very small

- Not every Snellen chart has a 6/7.5 line

- Test chart must be positioned accurately at 6m

- Charts at shorter distances than 6m and scaled to 6m must be accurately scaled

- +8.00D refraction limit does not specify whether it is the mean sphere power or “highest powered meridian”

- Hyperopes often become more hyperopic as they get older, so may start off less than +8.00D before crossing the +8.00D boundary (as they can accommodate through the lens as they get older)


what is there no statutory requirement in UK legislation of for group 1 drivers and what applies to them instead

- for fields of vision
- but the Second EC (european) Directive applies


what UK rules are there for european drivers who want to drive in the UK

- if they come to the UK, they can drive for up to one year without a UK licence
- they are allowed to use bioptic telescopes when driving, even though it is not a UK rule


when will a visual field standard usually be applied to a driver

when there is evidence that a defect exists


what are the standards/rules for safe driving defined as, (which apples to a patient who has a existing visual field defect)

- The minimum field of vision for safe driving is defined as a field of vision of at least 120º on the horizontal measured by the Goldmann perimeter using the III4e settings (or equivalent perimetry).

- In addition there should be no significant defect in the binocular field which encroaches within 20º of fixation above or below the meridian.


what is the minimum field of vision required in the horizontal meridian and what must this specifically be measured by


the Goldmann perimeter using the III4e settings (or equivalent perimetry).


what is the minimum field of vision required binocularly in the vertical meridian

no significant defect in the binocular field which encroaches within 20º of fixation above or below the meridian

By these means homonymous or bitemporal defects which come close to fixation, whether hemaniopic or quadrantopic, are not accepted as safe for driving.”


a driver cannot have any __________ in the ___________ _____ degrees of visual field all ___________

a driver cannot have any defects in the central 20 degrees of visual field all around


what rule about horizontal visual field requirements has been changed and since when

- a minimum of at least 50 degrees visual field in the outer half of the visual field both sides must be present
- a new rule from 2012


what type of visual field test is the group 1 licensing decisions currently based on

the outcome of the binocular Esterman test


what visual field machine uses the binocular Esterman test carried out on group 1 license holders

the Humphrey Field Analyser (HFA)

not allowed on the Henson


how are the stimuli presented with the Esterman test and what results regard the test results as invalid

- a bright stimulus (10dB) which uses supra threshold at each of 120 locations within the visual field

- If more than 20% false positives then the test is invalid


at what distance is the Esterman test carried out and how long does it take

- Test carried out at 1/3rd metre
- 4 to 5 minutes for the test


list 4 disadvantages of the Esteman test

- Stimuli arranged in a pattern that was designed to predict a person’s mobility (walking) performance

- Number of locations tested within the most functionally-relevant area of a driver’s visual field is very limited,
only 34 locations tested within the central 20, no locations within the central 7.5, and a predominance of these central locations falling in the lower half of the visual field (22 versus 12)

- Can only detect the densest of scotoma(ta) (as only 10DB higher/supra threshold)

- Fusion difficulties