Cardiff 5667R Combined Contrast Test
The Cardiff 5667R Combined Contrast Test is designed to test contrast sensitivity in toddlers and young children. Like the Cardiff 4740R Standard Acuity Test, this test uses vanishing optotypes and non-verbal assessment to carry out the evaluation. As a result, it is also suitable for testing contrast sensitivity in older children and adults with intellectual impairment.
Features and Benefits of the Cardiff 4667R Contrast Test
- A visual testing kit designed to determine contrast sensitivity
- Designed for testing toddlers and young children
- Suitable for older children/adults with intellectual impairment
- Tests sensitivity levels from 2.17 to 100
- Kit consists of 36 laminated cards with vanishing optotypes
What is a Contrast Sensitivity Test?
Contrast sensitivity is the ability to detect large but faint targets. There are some pathological conditions that reduce contrast sensitivity without impairing visual acuity, and a contrast sensitivity test can help to identify these conditions.
How the Test Works
This testing kit includes 36 laminated cards, each with a large vanishing optotype consisting of a light band bordered by two darker bands. The degree of contrast between these bands decreases across the card series, and in totality the test covers 12 contrast levels using three cards at each level.
The test cards are shown to the patient one by one, with the examiner noting the eye movements of the patient when shown each card. When the optotype shown to the patient lies beyond their contrast limit it merges with the background, becoming invisible to them. The examiner will be able to detect that the optotype lies beyond the patient's contrast limit by observing their eye movements, and will then be able to quantify the contrast sensitivity of the patient.
Sensitivity Levels Tested
The contrast levels tested start at 46% and decrease to 1%, which equates to sensitivity levels from 2.17 to 100. When the Cardiff Contrast Test is carried out at a distance of 50cm the targets represent 1.9 cycles per degree (or 6/90, 20/300) and at a distance of 1m the targets represent 3.8 cyclesper degree (or 6/45, 20/150).
At a distance of 25cm the targets represent 1.0 cycle per degree (or 6/180, 20/600). Results from the test are presented in a manner that is consistent with scoring of the Pelli-Robson Contrast Test for adults.