After the Surgery: A Caregiver's Guide to Recovery and Red Flags with Dagny Zhu, MD

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When people think about eye surgery—LASIK, PRK, cataract surgery—they usually focus on the eye itself. The lens. The cornea. The technology. The lasers.

What almost no one thinks about is their eyelids.

And yet, for surgeons who care deeply about visual outcomes, comfort, and long-term satisfaction, the eyelids—and what’s happening right at the base of the lashes—can make or break a surgical result.

On a recent episode of In Focus, I sat down with Dr. Dagny Zhu, a corneal and refractive surgeon who is widely regarded as one of the most trusted voices in surgical education. She performs thousands of refractive and cataract procedures and teaches surgeons around the country how to optimize outcomes.

And what we talked about wasn’t the “sexy” part of surgery.

We talked about eyelid inflammation.
We talked about dry eye.
And yes—we talked about lash mites.

Because these “small” issues are often the biggest reason patients struggle before and after surgery.

The Tear Film: The Most Important Lens in Your Eye

One of the most important points Dr. Zhu emphasized is this:

Your tear film is the most powerful focusing surface in your eye.

Even more powerful than your glasses.
Even more powerful than the intraocular lens placed during cataract surgery.

A healthy tear film creates a smooth, clear optical surface. An unhealthy tear film causes fluctuating vision, glare, irritation, and blur—no matter how perfect the surgery itself may be.

And the eyelids play a major role in this.

The oil glands in your eyelids (called meibomian glands) produce the oily layer of the tear film. That oil keeps tears from evaporating too quickly. When those glands are inflamed or blocked, tears evaporate almost instantly.

Some patients’ tears disappear in two seconds or less.

That affects:

• How clearly you see

• How comfortable your eyes feel

• And critically—how accurate pre-surgical measurements are

As surgeons often say: garbage in, garbage out.

If the surface of the eye is unstable, the measurements we rely on for LASIK or cataract surgery can be off.

Blepharitis: Common, Often Silent, and Frequently Missed

Blepharitis simply means inflammation of the eyelids.

Many people assume they would feel it if something were wrong—but that’s not always true. A significant number of patients have blepharitis with little to no symptoms before surgery.

That’s why relying on symptoms alone isn’t enough.

During a careful exam, surgeons assess:

• Redness or inflammation along the lid margin

• Blocked oil glands

• Poor-quality oil expression

• Dry spots on the cornea

• Tear film instability

Even if a patient says, “My eyes feel fine.”

Because if blepharitis isn’t addressed before surgery, it often shows up after surgery—when the eye is already healing and more sensitive.

That’s when patients start saying:

• “My vision comes and goes.”

• “My eyes burn.”

• “I thought surgery would fix this.”

Lash Mites: The Part No One Wants to Talk About (But Should)

Yes—most of us have lash mites.

They’re called Demodex, and they live in hair follicles and oil glands throughout the body. In small numbers, they’re harmless.

Problems arise when they overgrow.

Demodex overgrowth is a major cause of blepharitis and dry eye—and it’s far more common than most people realize:

• Over 60% of patients with blepharitis have Demodex

• Over 50% of cataract patients show signs of it

• Nearly 50% of contact lens wearers have it

The key sign doctors look for is something called collarettes—cylindrical, cuff-like debris at the base of the lashes. When present, they are diagnostic for Demodex blepharitis.

And here’s the catch:
You only see them if the patient looks down during the exam.

If you don’t look for them, you miss them.

Why This Matters So Much Before Surgery

Eye surgery—whether LASIK or cataract surgery—is an intentional trauma to the surface of the eye. Healing requires a stable, healthy ocular surface.

If eyelid inflammation or Demodex is untreated:

• Measurements can be inaccurate

• Visual outcomes can be less predictable

• Post-operative irritation can persist for months

• Patients may be unhappy despite technically successful surgery

There’s also emerging evidence that cataract surgery itself may allow Demodex populations to increase afterward—possibly due to inflammation or steroid drops suppressing local immune defenses.

Which means pre-operative treatment matters even more.

Treatment Is More Targeted Than Ever

For years, eyelid inflammation was addressed with vague advice: “lid hygiene,” “warm compresses,” “try artificial tears.”

Today, treatment is far more specific.

Depending on severity, management may include:

• Preservative-free artificial tears

• Nighttime gels

• Prescription anti-inflammatory drops

• Medications that reduce tear evaporation

• Heated eye masks

• In-office oil gland treatments

• And, for Demodex specifically, FDA-approved prescription therapy designed to eradicate mites at the lash base

Treatment may begin weeks before surgery—and sometimes surgery is intentionally delayed until the ocular surface is stable.

That delay is not a setback.
It’s an investment in the outcome.

Explaining This to Patients (Without Freaking Them Out)

No one loves hearing the words “lash mites.”

The way it’s explained matters.

Dr. Zhu uses an analogy many patients understand immediately: the gut microbiome.

We all have organisms that live on and in us. Most of the time, there’s balance. When that balance is disrupted, inflammation follows.

This isn’t about hygiene.
It’s not about something you did wrong.
And it’s treatable.

Another analogy patients respond to: a dirty windshield.

If your windshield is smeared with dirty water, no matter how good the car is, you can’t see clearly. The tear film is your windshield. The eyelids control the wipers.

That’s when the connection between eyelids and vision finally clicks.

A Note on Lash Extensions

This conversation wouldn’t be complete without addressing lash extensions.

They don’t automatically cause problems—but they can:

• Trap debris

• Discourage proper lid hygiene

• Worsen mite overgrowth

• Increase evaporation

• Expose the eye to irritating adhesives and heat

In patients with persistent redness, itching, or irritation—especially those pursuing LASIK—lash extensions often complicate healing.

These are not easy conversations. But they’re necessary ones.

The Big Takeaway

Successful eye surgery doesn’t start in the operating room.

It starts with the ocular surface.
It starts with the eyelids.
It starts with looking down—literally.

Blepharitis and lash mite overgrowth are common, often silent, and completely treatable. When addressed early, they improve comfort, clarity, and long-term outcomes.

If you’re preparing for eye surgery—or struggling after one—don’t overlook the smallest structures.

Sometimes the biggest difference comes from the places we used to ignore.

Want to Learn More?

This is just the beginning. In upcoming episodes, we’ll explore:
-How screen time and digital habits are shaping our kids’ development
–The connection between vision and overall health
–What you need to know about common eye procedures like LASIK and cataract surgery
–Practical ways to advocate for your child’s visual needs

You can subscribe to my podcast, In Focus, anywhere you listen—or follow along on Instagram for updates and tips.

Watch this episode on Youtube right now!

Thanks for reading—and for doing what you can to protect your child’s vision, one step at a time.

– Dr. Rupa Wong
Pediatric Ophthalmologist | Surgeon | Mom of 3

This episode is brought to you by The Pinnacle Podcast Network! Learn more about Pinnacle at learnatpinnacle.com