What is a Visual Field?
Visual fields is a term used to describe everything you can see, straight ahead and to your left and right, whilst your head is facing forward.
Remarkably, we take our field of vision for granted as we go about our daily lives. We don’t really have to think about it because we only need to use a single point in our central vision in order to see clearly. Everything else, we accept as being seen ‘out of the corner of our eye’.
In glaucoma, visual fields machines can only detect damage to our optic nerves, once 40% of our field of vision is already lost. This is why glaucoma can go undetected for many years before it is diagnosed and this is also why frequent and regular examination are important.
How can we check Visual Fields?
There are many machines available to measure an individual's visual fields. West Malling Opticians use the same machines found in the eye departments of hospitals.
The ZEISS Humphrey's Visual Field analyser is regarded as the most accurate machine available to measure the sensitivity and extent of your visual fields.
The test is painless and involves flashing a series of random lights in your peripheral vision at varying levels of brightness. You are required to respond every time you see a flash of light by the press of a button. The machine prints out the results showing us how wide and sensitive your field of vision is.
Why is it important?
Visual fields is the best way to monitor the progression of eye diseases like glaucoma. In the initial stages of glaucoma, the visual fields is constricted and then if left untreated, can lead to TUNNEL VISION and ultimately TOTAL BLINDNESS.
Visual fields can also be used to identify unexplained headaches and can be used to locate serious conditions, like brain tumours.
Does Visual Fields effect my Driving?
The answer is YES! Drivers must have a full visual field to be legal to drive and any effect on the visual fields can impair your ability to judge distances correctly.
As an official visual fields test centre for the DVLA, we carry out an Esterman Visual Fields on behalf of the DVLA, this test is specifically for drivers.