Optometry and Opthalmic Services

Heathrow Medical Services provides a complete range of optometry services for Aviation, Maritime and Occupational health purposes. This includes detailed tests for visual acuity, visual fields, muscle eye balance and a wide range of colour vision tests including (Lantern, Ishihara, Lantern and CAD testing) .

The Colour Vision CAD Test is a quick and accurate way to check how well you see colours. It helps your eye specialist understand if you have any difficulty telling certain colours apart.

During the test, you’ll look at a computer screen that shows small moving coloured shapes. You’ll be asked to say which direction the coloured shape moves. The test is designed so that brightness does not affect your answers — it measures your true colour vision rather than how well you see light or dark differences.

The CAD test looks carefully at how you see along two main colour ranges:

• Red–green (used in most everyday colour tasks)
• Yellow–blue (important for detecting certain eye conditions)

Your results show how sensitive your colour vision is compared to normal vision.
This can help:

• Detect inherited colour vision differences (present from birth)
• Monitor colour changes caused by eye or nerve conditions
• Assess colour vision for jobs where colour recognition is important (for example, aviation, maritime, electrical or other transport work)

What to expect:

• The test usually takes approximately 45 minutes.
• It’s non-invasive and completely painless.
• You can wear your usual glasses or contact lenses.

After the test:

The optometrist will explain the results and what this means in relation to your desired profession

For further information please contact: [email protected]