This is the most common and easily overlooked cause.

The distal lens (observation window) and light guide window of the endoscope are coated with a special anti-fog/anti-reflective film. During long-term insertion, removal and cleaning processes, excessive water pressure or the use of rough cleaning cloths/cotton swabs will directly scratch this film. Although invisible to the naked eye, the effect is noticeable: the image is no longer clear, with a hazy appearance, and the contrast is significantly reduced.

Blood, mucus and disinfectant may splash onto the light guide window during surgery. If not thoroughly cleaned, residual stains will accumulate on the glass surface over time, forming a stubborn film that is difficult to remove. This greatly reduces light transmission efficiency, resulting in an increasingly dark and blurry field of view.

As a device requiring frequent bending, long-term use of an endoscope causes irreversible changes to its internal structure.

The insertion tube consists of multiple layers of braided steel wire inside, covered with medical-grade rubber externally. With increased usage, the steel wire layer becomes fatigued and the rubber layer debonds from the base, resulting in local bulges on the insertion tube surface.Effect: This disrupts the linearity of the optical path, causing aberrations in imaging (blurred edges, distortion), and an overall decline in image quality.

When you find that the bending angle of the lens is less flexible than before, or the image shakes slightly and focusing becomes difficult after returning to the neutral position, it is usually due to worn bending wires or loose bearings. This causes minor vibrations of the lens during operation, leading to blurry edges in the image.

Do not assume the interior of an endoscope is a “dust-free zone”. Over time, dust accumulates in the optical path system as well.

Although the endoscope is sealed, long-term high-temperature disinfection and alternating hot and cold cycles can cause the sealant to age and form tiny gaps. Dust and fine fibers from the air can enter the endoscope and adhere to the objective lens.Effect: It is like wearing a dirty pair of glasses over the lens. The image appears gray and hazy, and clarity cannot be restored through external adjustments.

In high-humidity environments, if the endoscope is not stored properly, extremely thin moisture films or mold spots may form on the surfaces of internal optical components. This type of blurring is usually uniform, accompanied by reduced contrast, and is extremely difficult to resolve.

In addition to hardware wear, your usage habits can also accelerate blurring.

The CCD/CMOS sensors of the endoscope camera deteriorate over time, causing color temperature drift. Without regular white balance calibration, the image will show overall color cast (yellowish or reddish tint), which is often mistaken for blurriness.

Setting the cold light source to maximum brightness for a brighter field of view accelerates light attenuation in the light guide bundle. It also overloads the camera sensor, resulting in image noise and highlight clipping, making the picture appear grainy and unclear.

Now that the causes have been identified, how do we fix them? Follow these three steps:

Send the endoscope to an authorized service center for deep disassembly and cleaning. Use specialized coating removers and polishing materials to eliminate stubborn stains and surface scratches. This is the lowest-cost and most effective maintenance solution.

If internal dust buildup or objective lens aging is the issue, optical path calibration or replacement of the objective lens assembly is required. If the bending section is severely worn, the bending wire assembly must be replaced.

Endoscopic equipment is rarely worn out from normal use; most problems are caused by improper care. Increasing blurriness during use is actually the device sending a warning: it is worn out and in need of maintenance.As a professional user, understanding these principles and performing proper cleaning and storage each time is the greatest responsibility you can take for your equipment.