Henry's left eye tended to drift outwards, a type of exotropia (outward squint), which caused double vision, especially when he was tired, even though his eyesight and depth perception were otherwise normal.

Over time, orthoptic eye exercises helped strengthen his muscle control, and a minor eye-muscle surgery tightened the alignment further. The Frisby Stereotest was used throughout his treatment to check that his 3-D vision stayed strong.

Today, Henry’s eyes work together comfortably, and his double vision is resolved. Here's his story.

It was first noticed when I was at primary school (I'm 16 now). My parents could see that my left eye wandered and moved independently of my right eye – it looked a bit “wobbly,” especially when I was tired. I was also getting double, sometimes even triple vision, although I’d learned how to correct it by “snapping” my eyes back into position – unless I was very tired. I told my parents, and they arranged for me to be tested. It hadn’t been picked up at school, and there wasn’t any vision screening when I first started at age 4.

It turned out I had a squint in my left eye, which meant that when I was tired or resting, it would drift outwards. I was quite clumsy and sometimes struggled to read the whiteboard. I wasn’t  at that point very good at ball sports or playing football with my classmates. 

No, I didn’t. I’ve always had 20/20 vision. The problem wasn’t with my sight itself – it was that the muscles around my left eye weren’t keeping it properly aligned. When my eye drifted, it caused double vision. 

They monitored my vision for a few years and tried using an eye patch, but that didn’t help. Then they gave me vision therapy exercises to do – they wanted to see if I could strengthen control of my “wobbly” eye through exercises, because they knew that when I really concentrated, I could hold it steady. Every six months I went for a check-up and was tested with the Frisby Stereotest. I liked that one, and I could do it – so I knew I had depth perception when I focused. When I was a bit older, it was decided that surgery would be helpful. I had the operation when I was in Year 8 (12 years old). 

They made a small incision into the muscle of my left eye to tighten it and improve control. Afterwards, I had some time off school while the stitches healed and I needed regular eye drops for a few weeks.

I had to keep doing eye exercises at home. One of them used a picture of two cats side by side – I had to focus my eyes so that I saw a “third cat” appear in the middle, and hold it there for 10–15 seconds. Another exercise used a dot-line card, where I focused on one dot at a time, keeping it single and sharp, making sure I didn’t see two side-by-side images. They were quite fun, but also hard work – I had to do about five minutes in the morning and again in the evening. (Note: 2 of the vision exercises charts are shown below).

Things are good. My eye hardly ever wobbles now, even when I’m tired. I still do vision therapy exercises occasionally to keep the muscles strong and aligned – what my orthoptist calls “check-in” vision therapy. If I start to feel my eye drifting, I do the exercises for a week or two and it gets back on track. Then I might do them again in a few months if I need to.

Although I can still make my eye drift when I want to – I describe it as going into my own special “vision world” – most of the time my eyes are aligned and working together properly. I have good depth perception and no double vision. I can’t say for certain that everything I feel now is because of the treatment, but I definitely feel happier and more confident. Maybe that’s partly just growing up – but I still like to think of being able to move my eyes like that as my “superpower!”