Symptoms
- Arm flops instead of holding position
- Clicking or rattling at the hinge
- Sunglasses feel loose or crooked on the face
- One arm is looser than the other
Likely causes
- CommonHinge screw backed out from normal useConstant folding vibrates screws loose over time.
- PossibleHinge pin or spring worn from repeated flexingSpring hinges especially wear out after years of use.
- PossibleScrew hole threads strippedRepeated tightening or a fall can strip the tiny threads.
- Less commonHinge barrel cracked (common on cheap plastic frames)Inexpensive frames sometimes use brittle plastic at the hinge.
What to do
- Use an eyeglass repair kit's small screwdriver to check if the hinge screw is simply loose.
- Tighten clockwise in small turns, testing the arm's motion after each turn.
- If the screw won't hold or the hole is stripped, add a tiny drop of clear nail polish or a dab of thread-locking gel to the screw before reinserting.
- If it's a spring-hinge design and the wobble is in the spring itself, this generally can't be fixed at home and the arm may need replacing.
- For a cracked plastic hinge, a repair isn't reliable long-term; treat the sunglasses as needing replacement or professional frame repair.
- Store sunglasses in a hard case when not worn to reduce hinge stress going forward.
Tools and parts
- Eyeglass repair kit
- Clear nail polish (optional)
When to call a pro
An optician or sunglasses retailer can tighten, repair, or replace a hinge, often quickly and cheaply.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.