Smiling Makes Your Eye Squint? What Synkinesis Really Is (And How to Manage It)

After facial paralysis, the happiest moment is often "finally, I can move again." But then a new frustration emerges: when you smile, your eye involuntarily squints. When you close your eyes, your mouth corner gets pulled. When you eat, your eye tears up.

This isn't your imagination. It's called synkinesis — one of the most common sequelae of facial paralysis, affecting an estimated 40%–60% of patients.

The good news: synkinesis isn't "incurable." It's a signal that you're training the wrong way.

What Is Synkinesis?

Normally, when you smile, only your zygomaticus and risorius muscles contract while your orbicularis oculi stays relaxed. But after facial nerve damage, regenerating nerve fibers may "cross-wire" — branches meant to control your mouth corner also connect to muscles around your eye.

The result: when you attempt one movement, another group of muscles that shouldn't be involved moves along with it.

Common synkinesis patterns:

• Oculo-oral: Eyes involuntarily squint or close when smiling
• Oral-ocular: Mouth corner gets pulled when forcefully closing eyes
• Brow-eye: Eyes involuntarily close when raising eyebrows
• Crocodile tears: Eye tears up while eating (gustatory lacrimation)

These aren't "weak muscles" — they're "confused muscles." That's why traditional "practice big expressions" approaches can actually make synkinesis worse.

Why Does Training Harder Make It Worse?

This is the biggest mistake facial palsy patients make.

In the early stages, doctors recommend facial expression exercises to stimulate nerve regeneration and prevent muscle atrophy. That's correct for the acute and early recovery phases.

But in the mid-to-late recovery period (typically 3–6 months after onset), the problem is no longer "can't move" — it's "moving imprecisely."

If you continue training with large, forceful movements, your brain reinforces the wrong neural pathways. Every time you smile hard and your eye squints along, your brain learns "smile = eyes must also move." The more you practice, the worse the synkinesis gets.

The correct approach: start with small, slow, low-intensity movements to retrain your brain's fine motor control.

3 Training Principles for Synkinesis

According to the 2023 Expert Consensus on Facial Nerve Function Training, synkinesis rehabilitation focuses on "separation" — training each muscle group to work independently.

Principle 1: Slow

Hold each movement for 3–5 seconds. Don't rush. Slow movement gives you time to sense which muscles are "sneaking in" so you can actively suppress them.

Principle 2: Small

Use 20%–30% effort. Don't chase maximum range. A tiny, symmetric, controlled smile is 100x more valuable than a crooked big grin.

Principle 3: Separate

Specifically train "move A without B" isolation:

• Practice smiling in front of a mirror, deliberately keeping your eyes open
• Practice gentle eye closure while keeping your mouth corner still
• When you notice synkinesis, stop, relax, and retry with even smaller movement

A Practical Daily Synkinesis Control Routine

Here's a low-intensity daily routine for synkinesis patients (about 5 minutes):

Step 1: Facial Relaxation Scan (1 min)

Close your eyes. From forehead to chin, feel each area for tension. Gently massage tense spots in circles for 10 seconds.

Step 2: Brow-Eye Separation (2 min)

• Gentle eye closure x5: Close eyes only, keep mouth corner completely relaxed. If mouth moves, reduce force and retry.
• Gentle brow raise x5: Raise brows only, keep eyes naturally open.

Step 3: Smile Separation (2 min)

• Smile at the mirror at 20% effort. Goal: mouth corners slightly raised, eyes in natural state.
• Hold 3 seconds each, repeat 5 times.
• If eyes start squinting, stop, relax, retry with smaller movement.

Key reminder: If facial tightness increases or twitching occurs during training, stop immediately. Synkinesis training is about "quality > quantity."

Track Your Synkinesis Progress

Synkinesis recovery is slow — typically 3–6 months to see noticeable improvement. But "not seeing change" often means "not recording."

We recommend a standardized assessment every 2 weeks:

1. Record 9 standard facial expressions using your front camera (neutral, eye closure, brow raise, smile, toothy smile, etc.)
2. Self-rate each: completion, symmetry, tightness, synkinesis presence
3. Log your training sensations and changes

Compare after 2 weeks. You'll notice the small wins — "my eye squints less when smiling today" or "my mouth corner isn't pulled as much when closing eyes."

Visible progress is the biggest motivation to keep training.

When to See a Doctor

Most synkinesis can be improved with home training, but seek medical attention if:

• Synkinesis significantly worsens after training
• You experience facial pain or persistent twitching
• Eye closure difficulty causes corneal dryness and pain
• No improvement after 6+ months of consistent training

Facial palsy recovery requires patience. Synkinesis isn't "broken training" — it's "crossed signals" during nerve recovery. With the right approach and enough time, most people see significant improvement.

Face Recovery Journal is a rehab companion designed for facial palsy patients. It offers 9-action standardized facial assessment, personalized recovery plans (including synkinesis control training), camera-guided exercises, and progress tracking. Record every change in your recovery and export complete reports for your doctor.

Download Face Recovery Journal