Should I buy a used camera lens on eBay if it has dust inside?

Yes—if it’s just a few small internal dust specks, the price is fair, and the seller accepts returns. Minor dust inside used lenses is common and usually does not affect photos.

Do not buy it—or only buy at a steep discount—if the listing shows or mentions any of these:

• “Haze,” “fungus,” “separation,” “oil on aperture blades,” or “scratches”
• Lots of dust, clumps, or a “cloudy” look when light is shined through it
• Stiff/rough focus or zoom rings
• Autofocus or aperture problems
• No clear photos through the glass
• No returns, vague description, or seller avoids questions

Before buying, ask the seller: “Can you confirm there is no fungus, haze, balsam separation, scratches, aperture oil, or functional issue, and that the dust does not affect images?” Save the reply in eBay messages.

Rule of thumb: a little dust is normal; haze/fungus/separation is the real red flag.