About coloured overlays
Coloured overlays are sheets of transparent tinted plastic that are placed over printed reading material to colour the page and text beneath. They help relieve visual stress and can significantly improve the rate and accuracy of reading.
Individuals with migraines, concussion, learning difficulties and other neurological conditions that experience light sensitivity often find reading difficult. They may experience the movement of letters, words or whole lines of text, flashing in the white spaces of the page, intermittent blurring, or the appearance of coloured auras or rainbows around words. The right colour of overlay can reduce visual stress by:
Calming the bright white of the page,
Reducing the contrast of black text against the white page, and
Altering the striped pattern created by text printed across the page.
Without help, the symptoms of visual stress can make it very hard to concentrate on the reading material and lead to eye strain, fatigue, headaches, nausea and sore eyes.
With the right colour overlay, reading becomes faster and more accurate, tracking improves as fewer words or lines are skipped, and discomfort is reduced because the material is less stressful to look at.
It is essential that a full eye examination is carried out to rule out and correct for any visual anomalies that may be contributing to these symptoms. Reading difficulties can be caused by the need for a simple prescription change or eye exercises.
Opticalm carries overlays from several suppliers to provide a wide range of colours and saturations.
How to find your right colour:
If you are not sure of your colour, there are a few ways to find out what might work best.
The Crossbow Education online visual stress assessment tool can help you find an overlay colour that is comfortable and reduces symptoms. While this is not a detailed system, it can give you a good idea as to the colours you are sensitive to, and the colours that you find more comfortable on screen.
Trial packs of reading ruler sized overlays are also available on our store. These are useful for finding the right overlay – or combination of overlays that works best to reduce symptoms.
Which Size to get?
Full-sized overlays offer the best results as they cover the whole page including the white space that often triggers discomfort. The full-sized overlays are also best when both hands are engaged as they are when playing an instrument or making notes. If required, overlays can be easily cut to use with smaller pages.
Reading Ruler sized overlays are convenient and can aid in tracking as they are moved with the text. They are small enough to be tucked away or used as a bookmark.
To use the overlay, place it directly over your reading material, making sure it has complete contact with the page so there is no space between the paper and the overlay.
Overlays have a matte or glossy side. While many prefer the matte side, the glossy side is sometimes preferred for the brightness of the colour.
Adjust the angle of the reading material to reduce reflection from lights.
The overlay colour may work best when placed over white paper and not be as effective when placed over different colours of paper.
If you find that the benefit changes over time, you may no longer need to use the overlay, or your optimal colour may have changed as your brain has adapted to the use of colour. Please contact us for further advice.
There are many research papers demonstrating the effectiveness of overlays in improving reading ability by reducing visual, perceptual and physical symptoms:
Overlays as a screening tool for precision tinted lenses
Overlays are a useful tool to identify individuals who might benefit from wearing precision tinted lenses to filter their whole visual environment.
While overlays are effective for reading, visual strain and discomfort are often experienced when performing other visual tasks such as writing or working from a smart board. A better and more convenient solution is precision tinted lenses. Opticalm offers assessment services to help you find the optimal colour for lenses. They can be selected with great precision and accuracy. The outcome will be more effective as a portable filter that you can wear in any environment or condition.
Overlay colour Not Equal to Lens colour
While both coloured overlays and coloured lenses can improve reading fluency, their optimal chromaticities differ. As such, the overlay colour cannot be used to select the lens colour.
When tinted lenses are worn, the entire visual field is coloured. The eyes adapt to the colour in a manner similar to the adaptation that occurs when the light source itself is coloured. The condition of adaptation is different for that of an overlay because it is just one surface colour among many colours, and it is illuminated with white light. It is because of this difference in adaptation that there is only a weak association between the optimal overlay colour and the optimal lens tint. The association is so weak that the colour of the overlay provides little, if any, guide to the colour of the optimal coloured lens.