Sight test equipment

We are often asked by patients what each piece of our equipment does, So here is a brief explanation and we are more than happy to offer a guided tour of the equipment during your eye examination.

Visual fields machine

A visual field test is conducted using a piece of equipment called a visual field screener (sometimes known as an auto-perimeter). During the test you have to look at a little spot in the centre of the machine (to keep your eye still) and respond when you see the target (usually a light that flashes on and off once), which will appear somewhere else on the screen.

The visual field test can be a good indication of the health of your eyes and indeed the whole of your visual system.

It is a useful part of the eye examination – for example, it is used in the diagnosis and monitoring of glaucoma, and it can show up many other problems as well.

Retinal Imaging

Retinal imaging produces a high resolution image of your retina, optic nerve, and blood vessels.  It produces a coloured image of the optic nerve head where the blood vessels and nerves enter and leave the eye. Retinal imaging allows your optician to see symptoms of eye conditions which need quick medical care in order to prevent vision loss.

Slit lamp

The front of the eye may look like a clear window and although it is just half a millimeter thick it has in fact many layers which are impossible to see with the naked eye.

The slit lamp is a high powered microscope with a very intense light source that provides a very detailed examination of these layers. Since there are many conditions which result in a “red eye”, only by detailed examination with this equipment can an accurate diagnosis be made.

Using the slit lamp with a specialist lens called a Volk, the optometrist can also evaluate the health of the optic nerve, macula, vitreous and retina.

To book an eye test or contact lens consultation, click the button below.

Electronic letter chart

While everyone is familiar with the old ‘eye test chart’, it is not as effective for children who do not know their letters, those whose English is poor or those who have other learning difficulties.

Our computer based chart can offer pictures, letters, numbers, coloured images in a line or singly to reduce confusion in understanding the nature of the test.

The chart is equally lit across its surface and each letter has exactly the same level of illumination thus avoiding the problems associated with having a variable level of light falling across the chart.


The eye’s shape is kept by fluid that comes in at the back of the eye and out near the front. Sometimes the drain gets blocked up for unknown reasons and the pressure inside the eye rises. If it rises too high it can compress the small nerves in the eye resulting in a loss of side vision (see visual fields for how this is tested).

We test the pressure with one of two instruments; one requires us to anaesthetize the eye with drops before touching the surface with a very sensitive probe, the Perkins tonometer.

Our preferred tonometer is called i-care. This amazing piece of kit does not require air or even drops to work. All it uses is a very light, single use probe that gently bounces off the front of the eye and is so gentle it can even be used on children.

To book an eye test or contact lens consultation, click the button below.

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