Visual Fields

Whilst looking straight ahead, everything in your line of vision to your left and right is known as your ‘visual field’.

A full visual field is a legal requirement for all drivers as any effects on the vision can impair your ability to judge distances correctly. It can also be used to assess and monitor unexplained headaches and more serious eye health conditions such as Glaucoma and tumours.

Glaucoma and other eye conditions can affect the field of vision so a threshold visual field test is the best way to monitor the progression of this eye disease. In the initial stages of glaucoma the visual field is constricted and if left untreated can lead to tunnel vision and ultimately blindness.

What is a Visual Field?

During our day to day lives, we very rarely need to think about our field of vision as we use a single point in our central vision in order to see clearly, therefore taking our field of vision for granted. Everything else, we accept as being seen ‘out of the corner of our eye’, within our peripheral vision.

A visual fields test will only detect the damage to our optic nerves once approximately 40% of our field of vision is already damaged and therefore eye diseases like Glaucoma may go undetected and it may be years before it is diagnosed, another contributing factor as to why frequent and regular examination are important.

Using a Zeiss Humphrey’s Visual field analyser, which is also used within the eye departments of hospitals, West Malling Opticians is able to measure the sensitivity and the extent of your visual field.

The test itself is painless and involves flashing a series of random lights within 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 can also be used to identify unexplained headaches and can be used to locate serious conditions, like brain tumours. It is also useful to have regular visual field analysis done as it is also used just to monitor your overall vision as well as your overall health of your eyes.

A limited field of vision can also compromise your driving abilities and therefore all drivers must undergo this test. 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.