CARDIFF PEDIATRIC CONTRAST TEST™
This test is designed for contrast sensitivity measurement in toddlers and young children, and in older children or adults who have compromising reasons for experiencing difficulty responding to typical age appropriate tests. In addition, the Cardiff Pediatric Acuity Test™ is available for acuity testing which employs similar administration techniques.
THE VALUE OF CONTRAST SENSITIVITY
Contrast sensitivity is the ability of the visual system to detect large but faint targets. There are some pathological conditions that reduce contrast sensitivity without impairing visual acuity, and this test will assist in the identification of these conditions. Reduced contrast sensitivity and reduced visual acuity often occur together, so some children with visual impairments may also have reduced contrast sensitivity. Tests for these two functions are complementary and obtaining a measure of both will give a fuller description of visual deficits than will one alone.
Children with visual impairments who retain good contrast sensitivity will benefit from enlargement of tasks and print as they see large faint objects well. A child with an equivalent acuity but with reduced contrast sensitivity has a much more severe impairment, and will not get the same benefit from enlargement. Large objects as well as small objects are difficult to see at low contrast. So a measurement of contrast sensitivity can help determine appropriate management of a child’s impairment.
Some progressive eye conditions will result in changes in contrast sensitivity, so that monitoring contrast sensitivity and visual acuity (and other visual functions) may be essential in determining progress of the condition.
THE PICTURES
Like its 'sister' test, the Cardiff Pediatric Acuity Test, the Cardiff Contrast Test uses vanishing optotypes. The pictures are drawn with a light band bordered by two darker bands, each half the width of the light band, all on a neutral gray background; thus the average luminance of the picture is equal to that of the gray background. If the picture lies beyond the child’s contrast limit, it merges with the gray background, and simply becomes invisible.
Treatment for visual deficits (including amblyopia therapies) can result in improved contrast sensitivity sometimes in the absence of increased visual acuity. Contrast sensitivity can therefore be an essential tool in monitoring therapies.
The pictures (house, train, boat, duck, car, fish) are all of the same overall size, but decreasing in contrast between the light and dark bands. The contrast sensitivity is given by the faintest bands for which the target is visible. There are 12 contrast levels, 3 cards per level, and start at 46% and decrease to 1%, which equates to sensitivity levels from 2.17 to 100. Developed by: Cariff University
- At 50 cm the pictures represent: 1.9 cycles per degree (or 6/90, 20/300)
- At 1 meter the pictures represent: 3.8 cycles per degree (or 6/45, 20/150)
- At 25 cm the pictures represent: 1.0 cycle per degree (or 6/180, 20/600)
A4746R Cardiff Pediatric Contrast Sensitivity Test & occluding glasses — $ 1500.00 USD