Primer on Stroke-related Vision Loss

You push open the heavy oak doors of the pub and are instantly hit with a barrage of jovial sounds mixed with the scent of a strong alcohol and sweat cocktail. 

Scanning round the establishment, you quickly locate your friends and make your way to the empty seat left, you presume, for you. 

And then the drinks start. 

After a few rounds or more, you start to notice a numbing sensation on the left side of your body. Your friends comment on how your left eye and mouth are drooping. You try to say that something seems wrong, but it all sounds garbled and nonsensical.

At first, you blame it on the alcohol, but then you realise that you can no longer move your left arm. You start panicking. 

You’re having a stroke. 

The next thing you remember is waking up in a hospital room. It’s dark and you’re alone. 

You mentally check over yourself. Arm works. Face seems to be as expressive as ever. Mental calculations are tough, but you were never good at them anyway. Words sound clear enough. 

Footsteps gradually increase in volume and you realise that they are coming to you. 

You quickly close your eyes as light suddenly invade your eyes. As you become accustomed, you tentatively open your eyes. 

But you can only see half of what you would normally see. 

One side of your vision is gone.


Strokes occur when a part of the brain is deprived of oxygen. It is life threatening and can leave the victim/survivor with a series of conditions, ranging from mental to physical to cognitive. 

There are also various visual problems that can arise. Here are some of the most common stroke related sight loss conditions.  


Visual field loss

This is when parts of vision is lost. Hemianopia is when one half of vision is gone so those with the condition will only be able to see either the left or right half of what they are looking at. 

It is also possible to lose central vision, which may mean that it is not possible to directly look at something. 


Eye movement complications

Strokes can affect a victim’s control over their eyes. This may mean that the eyes are unable to coordinate with each other, which can cause diplopia (double vision). 

Some may also experience an uncontrollable wobble of the eyes (nystagmus) which can result in reading difficulties. 


Trouble with visual processing

Strokes can disrupt the way information is passed from the eyes to the brain and how that is processed. This miscommunication can often result in visual neglect, which is when something that is seen is not processed and therefore does not register with the individual. You may find that these individuals will unintentionally ignore people or objects because their brain has not interpreted the data sent by the eyes. 

The other extreme is also possible as many will experience hallucinations caused by processing errors by the brain, giving them images of things that aren’t actually there. 


Due to the wide range of visual conditions suffered by stroke victims, there is no one-fix-for-all. Treatment can help the victim cope and adapt to their vision loss, and can come in the form of rehabilitation, accessories, or smart glasses, depending on the exact nature of their condition. 

Some people will find that their vision improves for up to 6 months after their stroke. But again this depends on how well their brain heals after the initial damage. 

stephen hicks oxsight cofounder

OXSIGHT Co-founder Stephen Hicks on the HealthRedesigned podcast

oxsight on healthredisned podcast


OXSIGHT co-founder and head of innovation Stephen Hicks was invited onto the HealthRedesigned podcast to talk to Matt from Hanno.

They discuss neuroscience, delve into augmented reality, and how OXSIGHT is helping those with vision problems.

This is a rare insight in the more technical side of OXSIGHT and what we are working on and the challenges that need to overcome to help as many people as possible.

Listen below and enjoy!



Primer on Glaucoma

Glaucoma can trace its roots to Ancient Greece and is derived from the word Glaux which means owl. Ancient Greeks had a propensity to name diseases after animal due to their belief that this animal would then help the patient combat the disease. 

And so it is the owl that plays a central role in combating Glaucoma. 

Ancient Greek gem showing an owl taking centre stage in the fight against eye disease

Ancient Greek gem showing an owl taking centre stage in the fight against eye disease. []

Glaucoma is an eye condition where the optic nerve is damaged. This is normally caused through buildup of fluid in the eye which increases pressure. The pressure can injure or exploit a pre-existing weakness in the optic nerve. 

The effects of this damage may not be noticeable at first due to it normally developing over many years and primarily affecting peripheral vision. Because of this it is advised to take regular eye tests as this is usually how glaucoma is detected. 

Due to the variable nature of the cause, there are five main types of glaucoma, with most characterised by patchy blind spots in peripheral or central vision of both eyes. 

  • Primary open angle glaucoma is the most common type and is characterised by slow damage to the optic and changes to eyesight. 
  • Closed angle glaucoma occurs when eye pressure rises suddenly and can be very painful.
  • Normal tension glaucoma is when the pressure is within the normal range but damage to the optic nerve still happens. 
  • Secondary glaucoma is a result of the presence of another eye condition, an injury to the eye, or certain medication or treatments. 
  • It is also possible to be born with an improper drainage system in the eye causing congenital glaucoma.

Currently, there is no cure to restore the vision of someone with glaucoma. However, it is possible to stop or slow the degradation of vision and stave away permanent sight loss by controlling the level of pressure in the eyes. 

Eyedrops are the most common form of treatment with many people using them daily for many years. For some, it may be necessary to have laser eye treatment or surgery to help control the pressure. 

Recent developments have seen specialty glasses produced which can condense a wider field of view and display it in a patient’s more narrow field of view, effectively replacing part of their lost vision. More and more people are finding these smart glasses useful in their daily lives and the future points towards more advanced developments and further innovation in this field.

Primer on Retinitis Pigmentosa

“It’s like walking around while looking through a narrow tube. Then at night, imagine wearing thick, heavily darkened sunglasses. The irony is that, during the day, I actually need to wear sunglasses due to my intense light sensitivity.” 

James C Laird, Retinitis Pigmentosa

Imagine what it would be like to not be able to fully see a scene from your favourite TV show, to only be able to see the nose of your loved ones, to have to read your favourite book letter by letter, to live your life one jigsaw piece at a time. 

This is what it can be like for those with retinitis pigmentosa (RP). 

RP is a group of disorders that involve the breakdown of photoreceptor cells in the retina, a part of the eye that translates light into usable information for the brain. 

This can mean that those with RP will experience night blindness (one of the first symptoms) as well as a gradual decrease in their field of view. However, because retinitis pigmentosa is caused by a change in any one of over 50 genes, each case is different. Some may have perfect central vision, but are limited to 3 degrees field of view. Others may have small patches of clarity dotted around their vision. There are even those who experience kaleidoscopic sights.

RP is an inherited disorder and can be passed on to a child by parents who do not show signs of the condition. Conversely, parents with retinitis pigmentosa will not necessarily pass on the disorder to their children. 

While currently there is no cure for RP, there has been much work done to make life easier for those with the condition. Smart glasses, like OXSIGHT Crystal, are able to potentially increase the field of view for those with usable central vision allowing users to do things they were not able to previously. There has also been much research into genetics to find a way to reverse the degradation, bringing hope for a cure in the future.

For more information on RP, see RNIB’s full guide.

The state of gene therapy and stem cell treatment for blindness

Many people in the visually impaired community are (understandably) excited about the prospect of using gene therapy and stem cells to potentially cure blindness.

While there have been encouraging developments in these fields, on the whole it is still early stages.

In December 2017, the U.S. Food and Drug Administration (FDA) approved the clinical use of voretigene neparvovec (Luxturna), the first gene therapy for any condition to be given the go ahead. This comes off the back of over 10 years of research and clinical trials, and is aimed at only those with an “inherited retinal disease caused by mutations in both copies of the RPE65 gene and who have enough remaining cells in the retina”.

There are more than 250 genes involved in the development of blindness.

When it comes to stem cells, there have been two well publicised trials involving patients with different forms of Age-Related Macular Degeneration (AMD). While the results were promising, the sample sizes were very small (7 in total) and they had only undergone the first phase of trials. 

Generally it may take at least 3 trials before being submitted for approval by governing bodies. So while some may claim that these “could lead to an ‘off-the-shelf’ treatment within five years”, the timeframe makes this extremely optimistic. 

In an analysis by the National Health Service (NHS), they concluded that the 2018 results from the stem cell trials conducted by University College London, Moorfields Eye Hospital and Pfizer were “in its very early stages – bigger longer term trials will be needed to be sure it’s safe and effective”. For context, the phase I trials took three years and only included two patients. Unfortunately, there has not been any more updates since.

One of the more recent trials comes from UK-based biotech company ReNeuron Group. They had started Phase I/IIa clinical trials in the US with their human retinal progenitor cell (hRPC) therapy candidate for retinitis pigmentosa (RP) earlier this year and presented some of their early findings at the sixth annual Retinal Cell and Gene Therapy Innovation Summit in Vancouver, Canada, on the 26th April.

And while progress made has been encouraging, the trials have only been conducted with three people for less than half a year each. 

With number of hurdles needed to be overcome, one can only speculate when these treatments will successfully come to market, if at all. 

On the other hand, technology has seen tremendous growth and plays an ever increasing role in aiding those with a visual impairment. From wearables to apps, accessories to services, there are many potential solutions out there that are able to bridge the gap until a permanent solution is found.

OXSIGHT Signs Partnership with Samuels Opticians

Low vision specialist, OXSIGHT, have signed a partnership with Samuels Opticians to help make visual aids more readily available to those with sight loss in the Midlands.

OXSIGHT glasses use revolutionary imaging technology, built within Epson Moverio smart glasses to enhance the remaining sight for those living with peripheral vision loss caused by glaucoma, retinitis pigmentosa, and other degenerative eye diseases. The completion of this agreement increases the number of partners OXSIGHT have and further improves their ability to provide low vision services to the visually impaired community.

Samuels Opticians provide leading eyecare services and is run by Tony Samuels, who has over 40 years experience as an optician. Previously, Tony Samuels had set up an award-winning low vision clinic at Manor Hospital Walsall. He has two clinics in the Midlands and is excited to be part of this new venture.

“As an optometrist I have specialised in aids to assist people with low vision for nearly 40 years,” commented Tony Samuels.

“OXSIGHT is at the forefront of this technology with a unique low vision aid which is designed for those who have peripheral loss of vision compared to most aids designed for those with a loss of central vision. It is only recently that modern technology has been used to help such people. The look of delight on a successful OXSIGHT user and their family says it all. I am delighted to have been chosen by OXSIGHT as their clinical partner for the Midlands and look forward to helping as many people as possible.”

To mark the occasion, OXSIGHT will be joint-hosting an open day at Samuels Opticians in Solihull on 29th June, offering demonstrations of the glasses along with talks from current users.

OXSIGHT users have experienced an increased field of view of up to 68 degrees. Many utilise the different modes on offer to enhance their remaining vision and experience sights they thought they had lost forever.

“I’ve used super colour mode whilst sorting out my washing. It is really good for that as I could tell the difference between black and navy socks,” said Julie, an OXSIGHT user. “I had given up trying different things before I had the glasses because it was upsetting that I couldn’t do certain activities. However, these glasses are giving me a new enjoyment in life.”



OXSIGHT is a fast-growing digital eye care technology company established in 2016 as a spinout from Oxford University. It has developed a portfolio of products that are transforming the lives of the visually impaired, their friends, colleagues and the community around them.

It makes glasses that can make a real difference to people with conditions that cause peripheral vision loss. These include Glaucoma, Diabetic Retinopathy, Retinitis Pigmentosa, Myopic Degeneration, Retinopathy of prematurity and other degenerative eye diseases. Its glasses have also helped people with a visual impairment caused following a stroke, such as homonymous hemianopia.

The company has worked in partnership with leading global players from both the visually impaired community and the technology sector. These include Google, The Royal National Institute of Blind People (RNIB), Moorfields Eye Hospital, Guide Dogs Association and The Royal Academy of Engineering.

OXSIGHT is building a network of clinics in the UK and has operations in Europe, India and China.


Contact information:

Tel: 01865 580255


OXSIGHT Team Running for Retina UK

Less than 50 days to go until OXSIGHT Customer Care Manager Shaun Claridge sets off over the gruelling 26.2 miles of the London Marathon as part of the 2019 Retina UK team.

Having met the charities organisers, volunteers and members Shaun felt it was time to step up and try to help and is being supported by everyone in the OXSIGHT team as he attempts raise as much money as possible for Retina UK.

Shaun and his daughter with half eaten oreo cookies

Shaun’s training diet includes 5 meals of half an Oreo a day

The London Marathon is just the starting point for Shaun’s 20/20 Challenge where he will attempt to run 20 x 20 mile runs before the end of 2020.  That’s 400 miles of pure pain for Retina UK!  We will be sharing regular updates from Shaun’s 20/20 challenge, his progress, his injuries and just how much cake one man can eat in a year!

Henshaws reviews OXSIGHT glasses

Henshaws is a charity based in the North of England that have been helping those with sight loss and other disabilities for over 180 years. They work to help reduce social isolation and increase independence through empowering disabled people to go beyond expectations and achieve their ambitions.

They were kind enough to do an honest review of our Crystal glasses, which includes a quick demonstration and a look through the various modes we offer.

Ambassador Insights: A Rekindled Joy

Guest post by Anna.woman with short hair with oxsight crystal glasses

Anna has retinitis pigementosa and became an OXSIGHT Ambassador in December 2018. She is currently enjoying all the ways that OXSIGHT Crystal is enhancing her life. 

My mum was very keen on art and, during a visit to Paris when I was 15, she took me to see numerous galleries — mainly containing impressionist paintings. I’ve had RP all my life and I remember being able to see more as a teenager than I can now, approaching 50. The difference is subtle — my field of vision has always been poor, but my ability to deal with light and dark has diminished.

These days, I often find galleries poorly lit and sometimes can barely make out what is behind the glass when I look at a painting. My long-suffering and patient husband has come with me on many occasions, but the whole experience becomes tiring and frustrating. So, I’d pretty much stopped going.

I’ve tried the OXSIGHT Crystal glasses in two galleries: The National Portrait Gallery in London and the Tate, Liverpool. The impact that they have had is wonderful.

woman in a gallery looking at paintings with oxsight glasses and a guide dog

Anna using OXSIGHT Crystal at the gallery

There was not a single painting in the Portrait Gallery that I couldn’t see. Even for dark paintings, I could tune the glasses so that the image became lighter and possible for me to view clearly. I could zoom out, look at a wall of paintings with a couple sweeps of my eyes, then zoom in on the painting I wanted to focus on.

The good thing about the Portrait Gallery was that I knew every painting would contain a face, although some of them were a little confusing. The Liverpool Tate, with many modern paintings, was a little more challenging but I still enjoyed my visit very much.

In the Tate, some paintings were huge and I would start by minimising them to as small a size as possible so I could see the whole picture with just a few movements of my eye. Without the glasses, even if I had good enough light to see a painting clearly, I would need several minutes to scan over it as my field of view is so low (about three degrees). I explained to Rammy from OXSIGHT that if he imagined each painting as being a jigsaw made up of 100 pieces, I could only see about three of those pieces at any one time depending on how close I was to each painting and its size. So, on this basis, my eyes would have to move over thirty times to take in a whole painting.

woman in a gallery looking at paintings with oxsight glasses and a guide dog

Great day out with Inca, Anna’s guide dog

At one point, I was asked to turn and look at a painting. I did so, and said “Do you mean the round one?” Then I realised this was something that I wouldn’t usually say as, in normal life, I can’t just glance at a painting of an average size and determine what shape it is as I see so little of it at any one time. But, with the glasses on, I did this without even thinking.

I went to the Tate last weekend and many of the paintings are still clear in my mind, particularly the colours. The paintings were often more difficult to discern than the portraits I’d seen in London, but it didn’t seem to take my companions long to get me to the same level of appreciation that they were experiencing — a minute or two perhaps. Some pictures, less than 10%, I didn’t grasp but I imagine that modern art can be like this for everyone. With an audio guide, which the Tate didn’t provide for some reason, I think I would have been right up there with the sighted visitors.

Two very enjoyable visits, and further proof that art galleries can now play a more prominent role in my life than they did before. And especially pleasing as art was something that my Mum had wished me to appreciate.

OXSIGHT North of England Low Vision Roadshow 2019

15 shows in 15 days
21st January – 8th February 2019
Manchester, Sheffield, Preston, Morecambe & many more…

OXSIGHT present the North of England Low Vision Roadshow 2019. We have joined forces with local sight loss charities to launch a debut annual event across three-weeks to tour cities across the North to allow those who are living with peripheral vision loss to try out potentially life-changing technology.

Tuesday 22nd January – Sheffield Royal Society for the Blind 10-4pm
Wednesday 23 January – Sheffield Royal Society for the Blind 10-4pm
Thursday 24th January – Bradbury Fields, Liverpool 9-3pm

Monday 28th January – Galloways Southport 1-3pm
Tuesday 29th January – Galloways Preston 10:30-3pm
Wednesday 30th January – Galloways Chorley 10:30-3pm
Thursday 31st January – Galloways Morecambe 10:30-3pm
Friday 1st February – Sight & Sound, Rotherham 10-3pm

Monday 4th February – Leeds Jewish Blind Society 10-3pm
Tuesday 5th February – ABA Leeds 11-3pm
Wednesday 6th February – Princess St. Hotel, Manchester, 10-4pm in collaboration with Henshaws