29 November 2017
How good are your eyes when it comes to driving? We can legally travel at 70mph on certain roads – but are our eyes up to the challenge? Especially at night.
Mr Srinivasan Subramaniam, a Consultant Ophthalmologist at Spire Nottingham Hospital in Nottingham, says that it is important to have our eyes tested regularly and wear the glasses or lenses prescribed so that we are not only legal but safe behind the wheel.
So are your eyes in good driving order? Mr Subramaniam answers some much-asked questions.
Do you think that the law is strict enough on ensuring people can see well enough to drive?
The law currently requires you to be able to read a number plate (with your prescription glasses/contact lenses) from a distance of 20 metres and have an adequate field of vision.
But strict laws do not necessarily guarantee safety as there are people who fail to wear their prescribed glasses/contact lenses while driving.
Would you like to see the law changed?
The law is fine - it is the implementation that remains a problem! Not wearing the glasses prescribed is something that could be looked at. I believe that in some countries anyone who needs to wear glasses or contact lenses must carry a spare pair in the car so they don’t find themselves driving without the appropriate eyesight aids.
I think there could be random checks to see if people are using the appropriate eyewear and achieving the required visual acuity for driving.
Apart from short sightedness, what other eye conditions can affect the ability to drive safely?
Long sightedness can be equally debilitating. Both long and short sightedness however, can be corrected with glasses, contact lenses or surgery to achieve the minimum driving standard.
There are numerous other eye conditions that can affect your ability to drive e.g. cataracts, glaucoma, age related macular degeneration etc.
Different light conditions also affect the ability to focus, so a mild degree of short sightedness in the day may become exaggerated in dim light. This may well push a driver into having less than the legal minimum vision for driving at night. By the same token, in bright light, certain types of cataract have a much greater effect on the vision and could reduce visual acuity to below the legal limit to drive.
Can wearing tints or lens coatings improve the situation?
Tinted lenses may be useful in good or bright light conditions but, at night, could reduce the light going into the eye and therefore reduce the quality of vision. Photochromic lenses, a separate pair of tinted glasses may be a preferable option.
What about people suffering from cataracts?
The effect on driving of different types of cataract are listed below:
- Nuclear cataract - difficulty with night driving and in dim light.
- Posterior sub-capsular cataract - difficulty when driving towards the sun.
- Cortical cataract - usually glare, seeing a star burst type effect around lights such as street lights or car headlights.
In reality, many people have a mixture of the above types of cataract and symptoms may vary from person to person.
It is critical that your vision meets the eyesight standards and I would suggest that anyone with cataracts makes sure they have their eyes tested on a regular basis.