What are Harris Filters?

The majority of dyslexics have nerve fibres that transmit important information inefficiently between the eyes and the brain. This can result in poor control of eye movements and therefore increased difficulty with reading and understanding, loss of place on the line of text (sometimes with a line being repeatedly read because of inaccurate tracking) and poorer comprehension. Harris Filters are an advanced version of David Harris's award-winning range of special lenses that reduce or eliminate visual perceptual distortions, a condition that affects reading ability in almost 74% of dyslexia sufferers.

It is known from a phenomenon called the Pulfrich Effect that certain lenses change the speed at which information is carried along nerve fibres and this changes how objects are perceived.  David Harris believes from his work that when the correct visual filters are “tuned” for an individual they can help to improve the ease of reading. When the filters are prescribed, the left and right sides are dynamically “balanced” (called dynamic haploscopic prescribing) so that the left and right lenses in the glasses are always different when correctly prescribed.

Developed from earlier work in 1996, extensive clinical research has proved that Harris Filters can significantly ease reading difficulties - and many patients experience dramatic improvements.

The filter technology is now widely accepted throughout the world and used by 1000's in the UK and USA alone. Individually prescribed by a specialist practitioner and incorporated into spectacle frames, many wearers have also experienced improved self-esteem and dramatic improvements in literacy, handwriting, spelling and the symptoms associated with dyspraxia.

Visual Perceptual Distortion

Many dyslexia sufferers experience distortions when reading text. The symptoms can differ from person to person but common complaints include letters and words appearing to "dance" or move on the page, "rivers" (or "worms") of white running through the text (caused by the spaces between words and lines joining up) and many can lose their place on the page and repeatedly re-read the same line. Some confuse or reverse text (e.g. 'b' and 'd', 'was' and 'saw' etc) but there are many different problems that may be found.