How does an optical mouse work?

Mice come in all sizes, shapes and configurations on the market. There are ergonomic models with different handles to avoid health problems. Others are geared towards office use and have productivity features built-in. For us gamers, the models that really matter are the gamers, whose main difference is the precision of the sensor. But have you ever thought about how this optical mouse sensor works?

The technology is not exactly new, as it replaced the old “ball mouse” many years ago. However, it kept getting faster and more accurate, making it possible to use the peripheral on almost any surface. See below for details.

How does an optical mouse work?

The mouse’s function is to recognize your movements and transmit them to the computer’s cursor. To do this, an optical mouse has two crucial parts: a light source (LED or laser) and a CMOS sensor.

Image: Corsair

The function of the LED light source is to illuminate the surface directly under the mouse, for example the fabric of a mouse pad. Its light rays are channeled and directed through the transparent plastic cover located on the base of the device (see photo above).

These light rays are reflected directly onto the CMOS sensor, a kind of “camera” that captures hundreds of images of the surface per second to determine the position of the mouse, the scrolling speed, and the direction of movement of the peripheral.

optical sensor how the mouse works

Newer mouse models typically use infrared light sources that are not visible to the naked eye. Because of this, we don’t see as many models with blue or red light, which was very common until recently.

What does the DPI of an optical mouse do?

The acronym DPI, widely used by manufacturers’ marketing departments, stands for dots per inch, or points per inch. It represents the number of points where the mouse sensor divides the surface to be read. As a result, higher DPI values ​​result in much higher sensitivity to your movements.

Higher DPI values ​​result in much higher sensitivity to your movements.

Although this number gets a lot of marketing, in reality hardly anyone uses values ​​above 4,000 DPI. Most pro gamers even fluctuate between 800 and 1,200 DPI. The reduced sensitivity makes commands more accurate, ideal for targeting that small pixel for a sniper headshot.

We must emphasize that there is no ideal value. Each person should test the settings they feel most comfortable with. Many people even change the sensitivity to navigate through windows by accelerating the mouse pointer a bit. Easily accessible setting options are important, either via software or via buttons on the peripheral device itself.

Some gamer models like those from Corsair have so-called sniper buttons. By pressing them you temporarily decrease the sensitivity in DPI. It is an ideal setup for those who like to aim at long distances.

how does a mouse work

Corsair M65 mouse with dynamic DPI adjustment button

Query Rate: Accuracy is everything in the mouse

A very important value to look for when purchasing a gaming mouse is the sample rate or polling rate. It determines how many times per second the sensor works and updates the mouse position. More advanced gaming models operate at a rate of 1,000 Hz, or 1,000 updates per second.

The 500 clock is also quite common and sufficient in terms of performance as long as the sensor works accurately. Models below are not recommended as they can cause problems such as acceleration and losing track (spin out), causing your character to spin uncontrollably in-game.

What are the main advantages of an optical mouse?

Compared to the old models of ball mice, the main advantage of optical technology is the precision of tracking your movements. The sealed construction also prevents debris from entering the tracking mechanism, extending the life of the peripheral.

Optical technology has as its main advantage the precision of tracking your movements.

The latest sensors are also compatible with a variety of surfaces, including glass, although a completely flat, opaque surface is recommended for those who enjoy gaming. There are huge mouse pads that cover a large part of the table, ideal for allowing large movements without any kind of hindrance.

When shopping for a mouse, remember that it is important to consider factors such as size, grip and weight. Although several models are sold as the “best mouse ever”, in reality everyone has to find their ideal model.