What are Tumbling E Eye Tests?

Updated September 2024

Being able to see clearly is always important, but in some jobs, it becomes vital. For example, for drivers or pilots, you must be able to see so you can spot hazards and evade them where necessary.

However, visual acuity tests can take many forms, and each of them have different benefits and drawbacks, In this post, we’ll look at one of the less well-known eye test methods – the tumbling E test.

Though this is a commonly used test for certain professions, not many people are aware of what this test is. We’ll explain what the test is, why it is used and how it is set up.

What is the difference between a tumbling E Eye test chart and a standard eye test chart?

A tumbling E chart is a vision chart that only uses E’s. As with a ‘standard’ eye chart, they get smaller as they go down the chart but they also rotate direction. This allows people to describe the direction of each E (facing right, left, up, or down) to signify that they can see them clearly. There are 5 ‘E’s on each line and nine rows in total.

The name ‘tumbling E test’ comes from the way the letters seem to ‘tumble’ down the page as they rotate and shrink.

In contrast, the standard chart used in an eye test is called a ‘Snellen chart’. It is named after Hermann Snellen who originally designed the chart in the 1860’s. A Snellen chart uses different letters of the Roman alphabet, and the patient reads out each one.

Both types of chart are used for visual acuity testing, to help test patients’ strength of vision.

What is the most commonly used eye chart?

The majority of eye tests will use a Snellen chart as there is less risk of confusion when describing the letters. Tumbling E charts are only used when a Snellen chart is not possible for the reasons listed below.

When are tumbling E eye tests used?

Tumbling E charts are commonly used with people who are unable to read the letters on a standard Snellen chart. They are most often used with non-English speaking or illiterate patients. They are also used with young children.

However, they are used in other situations too. For example, as part of our contract with a local aerospace company, we carry out Tumbling E Eye Tests. These tests are required for inspection staff in order for them to receive their inspection stamp. If they fail the test they can’t get certified to carry out inspections on aircraft. This became mandatory in January 2011 through the UK National Aerospace Non-Destructive Testing (NDT) Board’s decision.

How do you do Tumbling E Eye tests?

Testing patients using a tumbling E vision chart is essentially the same as using a Snellen chart. Once the room is set up with the correct lighting, and the chart is arranged at the correct distance, a trained professional can carry out the test.

For this test you are asked to read across each line stating which direction the letter E is pointing in every time (this could be up, down, left or right). The tester will record how many you got correct, and how far down the chart you can see.

How far away is a tumbling E chart test?

The distance needed for a tumbling E test depends on the specific size of the chart used. Here at David Barber we use a portable test that must be set up 400mm away from the tested. We also use a test that is printed to a specific size for this distance.

It is also important the room has the correct light levels. This means a minimum of 500lux and a maximum of 750lux.

What lines should you be able to read on a Tumbling E chart?

If you can read the smallest line of letters on a tumbling E vision chart from a 20m distance, you have 20/20 (perfect vision).

If you can’t see this unaided, then corrective glasses should give you this strength of vision. With contact lenses, this becomes more difficult because they come at standardised intervals. However, you should get lenses that give you as close to this level of vision as possible.

What other visual acuity tests are there?

Tumbling E eye tests are rarely used in isolation. Instead, you may be asked to complete one or more other tests to get a full assessment of your eyesight. These other tests include:

Ishihara Test For Colour-Deficiency

The Ishihara test is designed to show that patients are not colour blind. You are shown a number of plates with a design on them. These designs are covered in irregular dots in two or more colours, and with one colour showing a number. You will be asked to identify the number, showing you can pick that colour out amongst the others.

Visual Field Test

Visual field tests measure your peripheral vision – or how well you can see above, below and either side of something.

This type of eye test can be done in a variety of ways that all revolve around the same principle. You look straight ahead to a single point, and signal when you see the test object (such as a light or solid object) appear in your peripheral vision.

Depth Perception Test

With a depth perception test, you are given a pair of 3D glasses or lenses and are asked to look at a series of patterns – usually of four circles. You are then asked to determine which circle looks closer than the other three.

Industry-specific health assessments to keep your staff safe

Our team of occupational health experts can run a range of health assessments to help ensure your staff are physically able to perform the tasks required of their job role. Get in touch with us today to find out about the specific tests we can carry out.