How Does Vertical Gaze Palsy Affect Vision in PSP?

One of the hallmark signs of Progressive Supranuclear Palsy (PSP) is a condition called vertical supranuclear gaze palsy. In practical terms, this means the brain struggles to send signals that tell the eyes to look up or down, with the ability to look down usually being affected first ^[1][2]. When you cannot look down easily, everyday tasks that happen below your eye level—like reading a book in your lap, eating from a plate on a table, or watching your feet as you walk down stairs—become incredibly difficult. This loss of downward vision is why you might suddenly find yourself spilling drinks, losing your place while reading, or feeling unsteady on your feet ^[3].

Why It Happens in PSP

The brainstem is a part of the brain that acts as the control center for many automatic movements, including the coordination of your eyes ^[4]. In PSP, there is a progressive loss of brain cells in this specific area, particularly in a region called the midbrain ^[5][6]. This midbrain damage means the eyes slowly lose their ability to move vertically (up and down).

Normally, if someone cannot move their eyes down, they simply tilt their chin downward to see the floor. However, PSP also commonly causes severe stiffness in the neck and trunk, known as axial rigidity ^[3]. Because the neck is stiff and the eyes cannot look down, it essentially creates a functional “blind spot” for anything below eye level.

Practical Impacts and Daily Workarounds

Because there is currently no medication that reverses the gaze palsy in PSP ^[7], managing the symptom is about adapting your environment so that you do not have to look down ^[8]. An occupational therapist (OT)—a professional who specializes in helping you modify your home and routines to maintain independence—can be incredibly valuable for these adjustments ^[9].

• Eating and Drinking: Spilling drinks or dropping food happens because your plate and glass are sitting below your direct line of sight. You are essentially trying to eat without being able to look at your food.
  • Workarounds: Raise your plate by placing it on a sturdy box or using a specialized raised dining tray. Use “scoop plates” (plates with a high lip) so you can push food onto your fork without looking. Switch to cups with lids and long straws, which bring the drink up to your mouth.
• Reading and Hobbies: Holding a book, smartphone, or tablet in your lap requires downward vision. If your eyes cannot track downward, words will disappear from your field of view or become exhausting to read.
  • Workarounds: Bring the reading material directly up to your eye level. Use adjustable book stands, angled lap desks, or clamping tablet holders to keep screens and pages right in front of your face. You may also want to explore audiobooks or text-to-speech features on tablets to give your eyes a rest.
• Driving: The inability to see below eye level can drastically impair your ability to safely operate a vehicle, as it becomes difficult to check the speedometer, see the pedals, or notice lower obstacles in the road.
  • Workarounds: It is critical to discuss this symptom with your doctor. They can refer you for a formal driving evaluation to assess whether you can still drive safely.
• Navigating Stairs and Walking: Not being able to see your feet or the ground directly in front of you increases the risk of tripping over rugs, missing steps, and falling ^[3][10]. People with PSP also have a strong tendency to fall backward (retropulsion), making standard walkers potentially dangerous because they can tip backward with you ^[1].
  • Workarounds: Use bright, high-contrast tape on the edges of stairs so they are easier to spot from a distance. Ensure your home has adequate, glare-free lighting, as visual contrast can be an issue. Always use handrails—ideally on both sides of a staircase. Remove all throw rugs and clutter from walking paths. Work with a physical therapist to find the safest mobility aids for you.

Vision Aids and Related Eye Issues

Specialized lenses called yoked prism glasses can sometimes help with gaze palsy. Prisms bend light, which can optically shift objects that are below your eye level up into your straight-ahead line of sight ^[11][12]. While these glasses do not fix the eye muscles, they can make tasks like reading or eating much easier for some patients ^[13]. An evaluation by a neuro-ophthalmologist is required to see if these specific prism glasses will work for you.

Additionally, some people with PSP develop problems with their eyelids ^[14]. This can include apraxia of lid opening (difficulty voluntarily opening the eyes) or blepharospasm (involuntary, forceful closing of the eyelids) ^[15]. If your eyes constantly feel forced shut, treatments like botulinum toxin (Botox) injections into the eyelid muscles can provide significant relief for blepharospasm ^[16]. However, Botox is often less effective and trickier to use for pure apraxia of lid opening, which may require other strategies like specialized ptosis crutches attached to your glasses ^[16][14].