How to Stop Sunglass Screws from Coming Loose Over Time
Published: July 25, 2025
By Ben Saperia, Founder of Faded Days Sunglasses
You're putting on your favorite pair of sunglasses and something doesn’t feel right. The hinge is a little loose—or maybe one of those tiny screws has disappeared entirely. It’s a common frustration, and it happens more often than you’d think, even with high-quality eyewear.
Long before I ever started working in the eyewear space, I noticed this happening to my own sunglasses. One day I looked closely at the hinge to figure out why they kept loosening. What surprised me was this: every time I opened the arm, the screw moved slightly—maybe a quarter turn. And when I closed it, it moved again, but not exactly in reverse.
That surprised me. I had always assumed the screw stayed completely still while the arm moved around it. But seeing it rotate slightly with each motion made me think: what if it doesn’t return to the exact same position every time? If I’m opening and closing the arms multiple times a day, and the screw shifts just a little bit each time—without resetting perfectly—then it’s only a matter of time before it works itself loose. It wasn’t a defect. It was just simple mechanics playing out in slow motion.
So why does this happen? And more importantly, what can you do about it? This guide breaks it all down—plus a simple fix you can do at home with something you probably already have on hand.
Why Sunglasses Screws Come Loose Over Time
Sunglasses may be lightweight, but they’re constantly in motion. Between daily wear and the environments they’re exposed to, a lot of subtle stress builds up at the hinges and bridge. Here’s what typically causes screws to loosen:
- Incremental screw drift – As mentioned above, if the screw shifts slightly each time the arm opens and closes—and doesn’t return to the exact same position—it can slowly work itself out over time. Even tiny rotational changes can add up after dozens of uses.
- Frequent movement – Putting on and taking off sunglasses throughout the day creates micro-movements that apply torque to the hinges.
- Vibration – Carrying sunglasses in a bag, leaving them in a car, or setting them down on hard surfaces introduces constant vibration, which gradually works screws loose.
- Temperature shifts – Heat expands materials and cold contracts them. These fluctuations can lead to loosening, especially in metal hardware.
- Natural oils – Sweat and skin oils can reduce friction at the screw threads, making it easier for movement and vibration to take effect.
This Happens Across All Brands and Price Points
One of the biggest misconceptions is that a loose hinge screw means the glasses or sunglasses are poor quality. In reality, this issue affects eyewear across the board—from budget frames to luxury designer labels.
Even the most durable hinges are still tiny mechanical parts exposed to real-world wear. It’s not a defect—it’s simply physics. That’s why many optical stores include complimentary screw-tightening as part of regular maintenance. It’s normal, expected, and thankfully, very easy to manage.
How to Fix It Yourself (Two Ways to Lock the Screw)
If your sunglasses screw is loose but still in place, there are two common fixes. One is simple and effective. The other is slightly more advanced.
Option 1 – Apply clear nail polish to the screw head (recommended):
- Tighten the screw gently using a small eyeglass or precision screwdriver.
- Apply a small dab of clear nail polish to the screw head—just enough to form a thin layer across the top and slightly overlap the edges. This creates a light seal that helps hold the screw in place without locking it permanently.
- Let it dry completely before wearing the sunglasses again.
This method helps prevent the screw from backing out with normal use. It’s safe, effective, and easy to undo if you ever need to replace the screw or adjust the hinge later.
Option 2 – Apply adhesive to the screw threads (for advanced users):
- Remove the screw carefully.
- Apply a small amount of clear nail polish—or a medium-strength threadlocker like Loctite Blue—to the threads.
- Reinsert and tighten the screw. Let it set before wearing.
This creates a stronger bond, but it’s more difficult to reverse. Use this method only if you’re confident in re-threading small screws without cross-threading or stripping the hinge.
When to Replace Screws or Visit a Repair Shop
If a screw has completely fallen out and can't be found, you can usually replace it with a standard eyeglass screw kit. These are widely available at drugstores and online, and they often come with multiple screw sizes and mini tools.
For stripped threads or bent hinges, a local optical shop or eyewear repair service can typically fix the issue for a small fee.
It’s Not a Design Flaw—It’s Normal Maintenance
Tightening sunglass screws is a bit like checking tire pressure or replacing a watch battery. It's a small upkeep task that comes with regular wear and tear.
Some frames might go years without needing attention. Others, depending on use and storage habits, may require a quick tune-up every few months. Knowing this is normal helps take the frustration out of the process—and once you know the fix, it becomes second nature.
Final Thoughts
A loose screw isn’t a failure—it’s just part of the life cycle of any well-worn pair of sunglasses. With a tiny bit of maintenance, you can prevent it from becoming a real problem and keep your favorite frames in rotation for years to come.
If you’ve ever spotted a small issue before it became a big one—or have a DIY tip of your own—we’d love to hear it. Share your story in the comments.
FAQs: Loose Sunglasses Screws
Why do sunglasses screws get loose so often?
Daily use, vibration, temperature changes, and skin oils all contribute to screws gradually working themselves loose over time.
Is it better to apply nail polish to the threads or the screw head?
For most users, applying polish to the screw head is safer and easier. It reduces risk of damage and is easy to reverse.
What’s the best way to stop a screw from backing out?
Use a precision screwdriver to tighten it, then apply clear nail polish to the head—or threadlocker to the threads if you're experienced.
Is this issue normal with expensive sunglasses too?
Yes. This is a universal issue across all brands and price points. It’s not a quality problem—it’s just physics and use over time.