It is important to accurately diagnosis the remaining levels of sight and hearing in someone who is deafblind.
Total loss of both functions is rare, so you will want to make best use of the senses that remain. For example, if your vision is affected, equipment such as glasses or magnifiers may help.
The two types of test that are commonly used to test your vision and hearing are:
Clinical tests - these identify how well you can see or hear compared with normal levels of ability. Standardised tests are used, such as the Snellen test, where you are asked to read letters from a chart.
Functional tests - these study how you actually use your sight or hearing. The tests use a wide range of different visual and audio stimuli plus medical examinations to determine your remaining levels of sight and hearing.
Diagnosing vision loss
If you start to experience problems with your vision, you should first visit an optician (a medical professional who specialises in designing corrective lenses to help with your vision).
The optician will run some tests to see how well your vision compares with normal, and will also be able to detect any eye conditions, such as glaucoma or cataracts.
If a problem is suspected and it cannot be treated using corrective lenses, you will be referred to an ophthalmologist (a doctor who specialises in conditions of the eye). They will run a series of tests and examinations to assess your sight and investigate any underlying conditions that may have caused loss of vision.
For more information, see Health A-Z: diagnosing visual impairment
Diagnosing hearing loss
If you start to experience problems with your hearing, you should first visit your GP. They will examine your ear for wax, infection or other causes of temporary hearing loss, and treat them accordingly.
If the cause of your hearing loss cannot be established, you will be referred to the ear, nose and throat (ENT) department of your local hospital for further assessment.
There are a series of tests that can be run to assess your hearing, such as an audiometry test, which uses different sound frequencies and volumes to determine what you are capable of hearing.
For more information, see Health A-Z: diagnosing hearing loss
Hearing tests: Audiometry is any testing that checks hearing.