Updated on November 11, 2026.
An optical mouse shines light onto the surface under it and captures tiny images of that surface. A processor compares details in each image with the previous one to work out how far and in which direction the mouse moved. Both LED and laser mice use this idea.
How a mouse turns light into movement
- An LED or laser lights up a small area under the mouse.
- A lens directs reflected light to an image sensor.
- The mouse compares texture in consecutive images to estimate movement along two axes.
- It sends movement counts to your computer. The operating system or game uses them to move the pointer or camera.
A smooth or transparent surface can give some sensors too little texture to track reliably. Dust in the sensor opening can also affect tracking. Try a plain matte mouse pad to see whether the problem comes from the surface.
LED versus laser optical sensors
| Light source | What to expect | What to check |
|---|---|---|
| LED | Common in office and gaming mice. Usually tracks well on a matte desk or mouse pad. | How it behaves on the surface you actually use. |
| Laser | Some designs can track on surfaces that are difficult for other sensors. | The model’s surface specifications. Glass tracking depends on the sensor design. |
For example, Logitech lists glass tracking for some Darkfield mice and specifies a minimum glass thickness for that feature. The light source alone doesn’t tell you how accurately a mouse will track. Check the Logitech Darkfield specifications.
What DPI and polling rate tell you
- DPI or CPI. Mouse makers usually say DPI. CPI, or counts per inch, describes how many movement counts the sensor reports per inch of travel. A higher setting gives more pointer movement for the same physical distance when your software settings stay the same.
- Polling rate. This describes how often the mouse reports to the computer. A 1,000 Hz setting gives a report interval of about one millisecond. Total pointer response time also depends on the rest of your setup.
- Tracking. If you’re choosing a mouse for a specific desk or pad, check that it tracks smoothly there at a sensitivity you can control.
See Logitech’s mouse sensor guide and our guide to what mouse polling rate changes.
Frequently asked questions
Is a laser mouse also an optical mouse?
Yes. It uses an image sensor and a laser as its light source. A product described simply as an optical mouse often uses an LED.
Does higher DPI make a mouse more accurate?
Higher DPI makes the mouse more sensitive to movement. For accuracy, look at how consistently the mouse tracks on your surface and whether you can control the pointer comfortably.
Why does my optical mouse jump on a glass desk?
Your sensor may struggle to find details on clear or reflective glass. Try a matte mouse pad. If you want to work directly on glass, check the mouse maker’s surface compatibility notes.