In certain job roles, it is very important to have adequate vision in order to do the job role correctly. If you are applying for one of these jobs you may be asked to do a pre-employment vision test as part of the pre-employment medical process.
Here are some examples of types of vision tests you might be asked to take as well as the roles that might require them.
Colour blindness
It is very important to ensure that electricians are able to distinguish between different colours of wires so that they don't accidentally work on live wires. For certain types of control system operators, such as airline landing operators, there is also a need to be able to distinguish between different colours. Most colour blind tests involve distinguishing a letter or a number in a square of gradiated colour points, as people with colour blindness will not be able to distinguish between the different shades.
Distance vision
For people who need to be able to view longer distances, such as truck drivers or train controllers, it is important to test distance vision before they get the role. In some cases, you may be able to use glasses or contact lenses when you get these tests done, but it is a good idea to ask the tester beforehand if you can use these aids. They may need to indicate the prescription of glasses or lenses that you use for your test results. This result is often measured using a standard eye chart, but newer tests can also include moving visual targets on a computer screen to best simulate the kind of vision that you will need to use in the workplace.
Close vision
For some roles, you may have to focus on small parts and fine detail for a long period of time. This includes people who work in laboratories as well as people who do fine machining. This vision is tested by holding up cards close to the face and getting the tester to distinguish details such as what letter or number is being indicated or how many fingers are being shown on a hand. Again you may be able to use your glasses or contact lenses, but it is a good idea to verify with the tester before the test starts.
If you are going for a job with specific vision requirements, you may need to undergo a visual test in your pre-employment medicals. If you are unsure of any details, please discuss these with your tester before starting the test.