PSP: Progressively Stealing My Vision

Today, it is the eyes. That is what I have noticed. That is what this piece is about.

Regular readers of this blog will know that I write about living with PSP in real time. This piece is no different. It was prompted by something that happened just hours ago.

This morning, at 1 a.m., which some people will insist is still night, I woke up and took off my sleep mask. I wear one because I am very sensitive to light and very bad at sleeping. Instinctively, as too many of us do too often, I reached for my phone to check the time.

I could not read it.

Not “it was a little blurry.” Not “it took me a moment.” I could not see the words. After getting up and cleaning my eyes with special wipes, it was better, but even now, having bolded and increased the text size, it remains blurry.

That moment, lying in the dark at 1 a.m., holding a phone I could no longer read, is what prompted this article.

Two of the three words in the name of my disease relate directly to its most distinctive feature: its effect on the eyes. The third word, progressive, describes its course with uncomfortable accuracy.

To quote the Alzheimer’s Society website (and there is a reason I am quoting them specifically, which I will come to in a moment):

“The word ‘supranuclear’ refers to the parts of the brain just above the nerve cells that control eye movement. When a person has PSP these areas become damaged. ‘Palsy’ means a person is unable to move a part of their body, in this case their eye. For a person with PSP, this means:

• they may find it difficult to move their eyes in the direction they want to look, particularly up or down
• their eyes may not co‑ordinate with each other, which causes blurred or double vision
• their eyelids may not open normally and may become stuck shut.”

So why quote the Alzheimer’s Society on a PSP blog? Because the two diseases share something fundamental: tau protein.

In both Alzheimer’s and PSP, abnormal tau accumulates in the brain and damages nerve cells. The difference is where it accumulates and how it folds. That shared biology has a significant consequence. Around seven out of ten people with PSP will experience dementia‑like cognitive symptoms during the course of the illness. Not Alzheimer’s dementia exactly, but problems with attention, planning, processing speed, and behaviour that arise from the same rogue protein doing its damage by a different route.

Whether I will be one of the fortunate three in ten who avoid that outcome, I do not know. What I do know is that I pray about it every single day.

Strangely, the eyes are not what I would have named as my biggest day‑to‑day concern, at least not until recently. Balance, rigidity, slow movement, and choking occupy far more mental bandwidth. Those are the symptoms that feel urgent.

And yet, so much of it circles back to vision. Balance, for example, is influenced by eyesight far more than most people realise.

The inability to look up and down, Vertical Eye Palsy, which I’ve had for some time, also feeds into stiffness of the neck and shoulders. When the eyes cannot do their job, the neck tries to compensate.

I should be precise here. The characteristic neck rigidity of PSP is not primarily caused by this compensation. The main driver is the neurological damage itself. Tau accumulation in the brainstem and basal ganglia causes axial rigidity, stiffness of the neck, trunk, and shoulders, directly. The backwards neck extension seen in PSP, called retrocollis, is a primary neurological symptom, not a workaround. The compensatory neck movement exists, but it is the lesser contributor.

Every time I have physiotherapy or medical treatment and lie down on a bed, looking up at bright overhead lights is immediately difficult. I often have to ask for them to be dimmed before I can even focus on why I am there.

A little about the impact of PSP on the eyes

Vertical Eye Palsy is not a footnote in PSP. It is its most distinctive clinical feature, more defining even than the falls or the rigidity.

My own diagnostic journey reflects this perfectly. Back in 2020, when my condition was still being labelled a Parkinsonism, I spent half a day in an eye clinic. I remember them saying, in effect, “The good news is there is nothing wrong with your eyes. The bad news is it’s your brain.”

The problems were neurological from the start. The eyes were the window, but the damage lay deeper. Vertical Eye Palsy appeared in my medical notes after a year or two. PSP was briefly considered in the second year. And yet it was not clinically confirmed until year five.

Five years. The eyes were signalling something different from classic Parkinson’s disease almost from day one.

Another under‑recognised feature is that between 60% and 100% of people with PSP experience tiny, involuntary eye movements called square wave jerks, even when trying to hold the gaze steady. Most have no idea they are happening. I certainly didn’t, until someone pointed them out.

PSP also disrupts blinking. At first, the blink rate drops, drying the eye surface and blurring vision, before often swinging the other way into spells of rapid, uncontrolled blinking. It is not one problem, but two, alternating.

Back to me

I also find myself involuntarily closing my eyes for varying periods throughout the day. And then there is the Vertical Eye Palsy itself, which makes it effectively impossible to raise or lower my gaze without moving my whole neck.

A neurotypical person, faced with this list, would probably be alarmed. And objectively, the picture is significant.

I no longer drive. I took myself off the road voluntarily because of my eyes. I could not reliably look up at traffic lights without moving my head, and combined with blurred vision, that stopped feeling safe, both for me and for other people. Surrendering my licence was not something imposed on me. It was a decision I made because driving no longer felt responsible.

I also struggle to recognise faces at a distance. Reading small text is difficult, which is why I moved to a wider‑screen computer.

I adapt. I use compensations. I will continue to do so, but until there are no more adaptations left.

The single most infuriating daily frustration, honestly, is glasses. Watching television and using my phone require completely different lenses. The constant swapping is maddening. People sometimes ask why I don’t use bifocals or multifocals, but I’ve been specifically advised against them because of the balance problems they create for people with PSP, who already have more than enough instability to manage.

I am calm about all this, maybe calmer than people expect me to be. But I wanted to write this piece because the eyes remain an under‑mentioned feature of PSP. Falls, speech, and rigidity tend to dominate the conversation.

In reality, the eyes sit quietly near the centre of it all. They compound other symptoms, limit daily life, and steadily narrow the world in ways that are easy to miss, until one night, you cannot read your phone in the dark anymore.

The eyes deserve a mention.