Visual processing is a term that is used to refer to the brain’s ability to use and interpret visual information from the world around us.

The process of converting light energy into a meaningful image for you to understand is a complex process that is facilitated by numerous brain structures and higher level cognitive processes. Your eye receives the image, sends it along the complex pathways of your visual cortex, to be processed by the brain.

For some people, these images get scrambled, or confused and misinterpreted, leading to visual processing problems such as dyslexia, Dyspraxia (DCD), migraines, some conditions related to autism (ASD), or other common perceptual issues such as “face blindness” or peripheral blur. 

Crowleys Opticians have invested in Visual Processing facilities in our stores as we feel the future of optical care will incorporate this important service for customers who are suffering from visual stress due to processing issues.

20% of people struggle with some form of visual processing issue where the eye is functioning perfectly, but the visual message being sent to the brain along the Visual Cortex is being misinterpreted due to a processing error.


Do you have light sensitivity issues?

Do you have difficulty reading, or writing?

Do you have difficulty perceiving faces or objects?

Do you have vision related headaches or are labelled “clumsy”?

more than just eye health

While optometrists primarily focus on the health of the eye, and any issues relating to vision, increasingly we are seeing that a third, very important aspect of how we see is overlooked; how the brain interprets the images sent to it from the eye, along the optic nerve.

If your brain misinterprets the images sent to it, it can lead to great distress, or life-long issues with a person’s visual processing. Another way of considering this is that the eye can be functioning perfectly, sending clear images to your brain. However, due to processing issues, your brain may be scrambling the image and creating a visual impairment.

This is common in Dyslexia, Dyspraxia, ADHD, migraines and other neuro-diverse conditions such as ASD. 

Visual Processing - Vision - MCAT Content

How Colour Helps

Difficulties with visual processing can be due to hyper-excitability of neurons in the Visual Cortex. This means that some of the cells in the visual pathways to the brain which deal with processing optical information work too fast and do not respond in the way they should. Colour can help to slow and calm these cells and therefore quieten the pattern of the text and improve visual processing.

Colour is needed to reduce the hyperexcitability and the colour prescribed using a Visual Processing system is very precise and specific to each person. This precise colour is then transposed into tinted glasses which help to reduce visual processing issues.

Crowleys Opticians use the ReadEye System which consists of a computerised assessment and prescribing instruments.

Different coloured lights are used to find the person’s optimum colour response. The colour is then recorded and a lens is tinted to the exact specifications and glazed into spectacles. The colour is individualised and may change over time.

who is affected?

Approximately 20% of the population are affected by visual processing issues. Not everyone needs corrective lenses but may still require this service.

Visual processing issues can be present in neurological conditions such as:

  • Attention Deficit Hyperactivity Disorder (ADHD)
  • Autism Spectrum Disorder (ASD)
  • Developmental Coordination Disorder (DCD) or Dyspraxia
  • Dyslexia
  • Migraines
  • Vertigo
  • Sensory Processing Dysfunction (SPD)
  • Prospagnosia or Face Blurring
  • Binocular vision and accommodative issues such as trouble refocusing from a white board to the page on the desk. 

Symptoms can be present in the absence of a diagnosis as well. While we have many patients referred to us from medical practitioners, self-referrals are also welcomed.

How Can Visual Processing help?

Visual processing can be used to help improve outcomes within the complicated conditions listed above. It’s important to note that detailed examinations need to be undertaken to see how visual processing can appropriately help with conditions such as migraine, dyspraxia and the others listed above. We can never tell until we sit and work with a patient and expectations must be set accordingly. This can be a long road, but it can lead to great outcomes.

By properly testing your sensitivities through ReadEye testing we can identify tinted lens solutions that may alleviate some of the symptoms you’re experiencing – such as words moving on a page, or certain lights leading to migraines, visual distortions (such as face blurring), or indeed coloured lenses which can calm a mind.


if you would like to know more about or visual processing services, email [email protected] or call us on 045 57 4444. We’ll answer your questions and arrange to have Grainne our expert speak to you.





Michael had been having problems with double vision. After exhausting opticians, and even surgery, his mum Jenny brought him to see Grainne. Here Jenny tells us about her and Michael’s experience.

“Michael (pictured) was in 4th class when lock-down started, pretty soon into home schooling I realized that he simply couldn’t see the screen or books. After several visits to our local optician – and two different types of glasses – he still had problems. He still couldn’t read digital clocks or displays, for example. He was also saying he was seeing double! This was very distressing.
Double vision
We were referred to a pediatric ophthalmologist and all scans were clear, but Michael still couldn’t read close up. He’d manage a line or two with great effort and was still seeing double. His frustration playing Xbox and trying to everyday things were increasing. Only after chatting to him did we realize that he thought everyone saw double!  
He’s the youngest of four and I thought he was a bit clumsy when he was little so we would be careful giving him his dinner plate. We’d all  help him not to spill.
After two consultant opinions and a number of opticians we were told Michael had “Convergence Insufficiency”. The decision was taken to try surgery. The plan was to move the muscle on one eye to draw it inwards in the hope of getting both eyes working together. It didn’t help at all, he had double vision in distance afterwards, which eventually settled, and we were devastated for him.
Considering visual processing
The option of further surgery held no joy for any of us with no certainty of a good outcome for Michael. It was heartbreaking watching him pretend he was okay with it.
A friend of mine told me about this amazing lady Grainne who worked in Newbridge,  so we booked the appointment and headed down one Tuesday morning. We initially had an assessment with one of Crowleys Optometrists and then went to Grainne. She had him sussed in no time, she figured out he had neuro-processing issue as well where there was a time lapse between seeing someone speak and hearing the words they said.
Going green!
Grainne adjusted room light colour. Dark green was Michael’s colour and adjusted with lenses and prism until he could see the sheet of words on the light box. She sent us home after over 3 hours to come back next day to figure out what he needed. The Crowleys team worked hard for Michael and in the end Michael was reading scripts that were too small for me to read with ease! The prescription was working!
Michael’s life transformed
Michael’s new green tinted glasses have TRANSFORMED his life. He’s reading books because he wants to. He can play Xbox and is much calmer. The delay between watching films on TV screen and hearing is gone. It’s been life changing for him.
I cannot express my gratitude to Grainne the Crowleys team in Newbridge enough in words. The day we picked up the glasses was pure emotional, listening to him reading down the test chart on Grainne’s desk. Then he read the menu in coffee shop after! He is beyond happy – so much so that he made a video about it! Thank you so much  from the bottom of our hearts.”



“My new glasses are brilliant! The moment I put them on in class, it was like a huge heap of relief being thrown at my eyes. I find my eyes don’t get tired and I am also working and listening better in class. It’s amazing!

These glasses allow me to zone in on the teacher’s voice, and background noises or voices are blocked out completely!”

Sophie, aged 14


“Ben is doing great with the new Visual Processing glasses. The school is very happy with him and are seeing a big improvement with him too. He find them very useful in the playground too!”

Elizabeth, Ben's mother


“Jessica is flying it with her new Visual Processing glasses. She lives in her yellow tinted glasses, while wearing the green tinted glasses on occasions when she feels it’s very bright.

Thank you so much. They make such a huge positive difference to her daily life.”

Claire, Jessica's mum


“In my early 20s, I began to get migraines. As I got older these intensified to the point where I would get cluster migraines and I couldn’t get out of bed. My migraines seemed to be connected to light sensitivity.

Since I’ve tried Visual Processing, I’ve discovered that a green tint in my lenses GREATLY reduces my migraines. I no longer get cluster migraines, and any headaches I do get are greatly reduced.”



Many people struggle with the effects of visual disturbances every day. Here are some examples.

Many people with visual disturbances or processing issues “mask”, or normalize what they see. They may not realize that others don’t see the world this way – this is especially true for children – and therefore think it’s perfectly normal.

However, these visual distortions are impacting their lives, and we may be able to help them.

If you recognize any of the visual symptoms below, get in touch.


A distressing visual disturbance where a patient’s peripheral vision is heavily impacted.

Another example.

Face Bleaching

Patient’s of ours have come to us never realizing that they should be able to clearly see a face.

Lower Field Loss

Some people may not clearly see the lower half of a face.


One of the rarer types of visual disturbances is where the brain superimposes animal faces onto the faces of people. This can be highly distressing, and often happens when someone is under stress.


Visual processing can have great results with conditions such as dyslexia. There are a number of conditions, associated with dyslexia, which is generally referred to as ‘visual stress’:

  • Visual dyslexia,
  • Meres Irlan Syndrome
  • Irlan Syndrome
  • Scotopic sensitivity syndrome

Often reading difficulties can be due to light sensitivity and headaches from exposure to disturbing visual patterns. It can be responsible for print distortion and rapid fatigue when reading. The severity of these symptoms can vary from person to person.


Visual stress can manifest in a number of ways, such as:

  • Movement of print
  • Blurring of print
  • Letters changing shape or size
  • Letters fading or becoming darker
  • Patterns appearing, sometimes describes as “worms” or “rivers” running through print
  • Illusions of colour – blobs of colour on the page or colours surrounding letters or words
  • Rapid tiring
  • Headache or eye-strain

All of these are symptoms of Dyslexia.

Here’s an example of why a Dyslexia person might see when they look at the page.


Here are some tell-tale signs you can look out for in loved ones who you think might be struggling with Dyslexia or visual stress:

  • Moving closer to or away from page
  • Becoming restless or tired quickly
  • Using finger as a marker
  • Skipping words and lines
  • Rubbing eyes and blinking excessively
  • Not making eye contact.
  • Fidgeting
  • Daydreaming
  • Sick tummy after school
  • Clumsy
  • Prefers one to one rather than groups
  • Face scanning

Visual stress is NOT dyslexia but can be particularly prevalent in dyslexic individuals. If visual stress is identified in a patient, prescribed tinted lenses are used to alleviative some of the symptoms.  Very often visual stress manifests itself when a child starts reading full text books.

How Do You Test for Visual Processing Issues?


A person will undertake a number of non-invasive examinations where their particular sensitivities will be identified. Our testing rooms are fitted with “lighting rails” which allow us to colour the room in a wide arrange of colours. By conducting tests under different colour conditions we begin to identify what colours your visual processing is sensitive to.





if you would like to know more about or visual processing services, email [email protected] or call us on 045 57 4444 We’ll answer your questions and arrange to have Grainne our expert speak to you.