Cerium overlays have been designed for use by children with reading difficulties. The use of an overlay has been shown by The Medical Research Council's Applied Psychology Unit at Cambridge to enable reading speeds to be maintained for longer periods and increased performance in visual search tasks. The same research study also demonstrated the colour selected will vary for each child.

Background information

For some people the process of viewing black print on white paper can produce symptoms of visual discomfort, distortion of the text and headaches. These problems are particularly common amongst those who have reading difficulties and dyslexia. Many of the symptoms given above can be relieved by the use of a specific colour. The colour required in most cases will be unique to each person.

Over many years there have been various trials and research projects carried out into the spectrum of colour. Although the mechanism by which colour helps is not fully understood, is sufficient evidence to justify the use of coloured overlays and the Precision Tinted lenses as determined using the Intuitive Colorimeter.

Before considering the possible use of colour, it is essential that a full eye-examination should be carried out. Any visual anomaly may be the result of a need for an ocular correction or for visual training. These aspects of vision must be investigated first and then investigated as necessary.

Overlays can be used for all reading tasks, although if the print is on a coloured background, the overlay may not prove helpful in that case. If the use of the overlay is successful i.e. there is continued use of the overlay for a period of approx. 4 weeks, then the prescribing of Precision Tinted Lenses using the Intuitive Colorimeter should be considered. The lenses there is a greatly increased range of hues available and the lenses can be made in different depths of tint. In addition, by using lenses, writing and also reading from the blackboard can be executed with the benefit of colour. It is important to note that the colour the lenses require is likely to differ to the colour of the overlay.

The colours of the Cerium Overlays have been selected using the Intuitive Colorimeter to ensure that, as far as possible, all colours are represented by the overlays and that the transmissions of them are approximately equal. The overlays consist of a robust transparent sheet that has a non-reflective surface, but one that allows the print to be clearly seen. The overlays may be superimposed on each other, but no more than two overlays should be used any one time due to the increasing density of tint. Imposition should be carried out only in e manner indicated on the recording chart.

The examination pack consists of- Two A5 sets of overlays, a pack of recording sheets, examination targets and full instructions for assessment.

Full size overlays (A4 size) are available and should be used for all reading tasks away from the test situation.