Lenses used more commonly in the US can reduce visual stress. We have identified that these weak low plus lenses, sometimes associated with yoked or base in prisms, which we have termed "stress relieving lenses (SRLs)", can be very beneficial for these children. It is amazing, as an optometrist, to see the changes these lenses make, the child often smiles, their reading speeds up and intonation improves. Look at the videos below to see these lenses in action
Unfortunately, about 5% of children are not helped with these lenses and therefore need vision therapy. Other children, though finding these lenses beneficial, still need vision therapy to fully develop their potential
Assessing best lenses to improve reading performance
Effect of wearing SRLs on the writing ability of a 7 year old
The video below shows the stress this young lady experiences when trying to look at a near target. When she has her glasses on, she can converge is a relaxed comfortable manner.
The video below shows the difference these lenses make to a child struggling to read. See the changes in reading range, comfort, head movement etc
As a result of this reduced strain, their reading is more relaxed, speedier and with improved intonation and better comprehension
My thanks to these young ladies and their mothers for allowing me to share these videos with you
Irlen syndrome, sometimes called visual stress is often treated with special tints in specs or the use of a coloured overlay, a sheet of plastic placed on printed material
However research carried out both in the US and in the UK has shown that most people experiencing Irlen syndrome actually have an undiagnosed binocular vision problem such as convergence insufficiency
For example, Arnold Wilkins, who developed the colorimeter stated 8 times in his book, Visual Stress, that closing one eye makes the "stress" illusions disappear, though he fails to make the obvious assumption that:-
"Visual stress (Irlen syndrome) is, in reality, a BINOCULAR VISION problem".
Our experience at Shaylers Vision Centre has shown that the majority of children with Irlen syndrome can be better helped with either Stress Relieving lenses or Optometric vision Therapy - a case of FIXING THE PROBLEM rather than using a STICKING PLASTER
Research carried out by Optometrist Geoff Shayler in 2002 at a school in Bournemouth, Dorset indicated a direct link between the range of clear, near focus and educational ability as defined by their SAT results, the smaller the range, the poorer the SAT score. In addition this study also showed a link between these ranges and their behaviour in school.
A simple measure
Take a piece of small news print, start with print about 25 cm from your child's face, can your child see it clearly?,[if not try moving in or out a bit to see if you can find a distance when it is clear. If blurred at all distances then child definitely has a viison problem], move the print slowly in until your child just starts to find the print blurred (gets difficult to read) measure distance from forehead to print (NP). Now move the print away from the face until it just starts to blur (gets difficult to read). measure this distance (FP). Divide FP by NP. i.e if. NP=10cm, FP=30cm, then the FP/NP ration is 30/10 =3. If FP/NP ratio is <3.5, your child has a visual processing problem, Between 3.5 and 4.5, may have a visual problem. >4.5 unlikely to have a "visual" problem but may still have a "sight" problem - i.e. if short-sighted will need specs to see clearly in the distance
In a second study carried out with optometrist Smita Trivedi, we identified that around 80% of children achieving grade 1 in their Key stage 1 SATs had an FP/NP ratio <3.5 whereas only 10% of children at grade 3 were within that range