Before the advent of optical and laser mice, a computer mouse used a weighted rubber ball that rolled across a mouse pad. However, mechanical-ball mice are now obsolete and have been completely supplanted by optical mice, which use an LED, a laser or other light-based technology to track movement and translate the coordinates of that movement to the computer. Optical mice need little cleaning and can be used on just about any flat surface, with or without a mouse pad. They don't work as well on reflective surfaces. Most optical mice plug into a USB port, rather than the older PS/2 mouse port.
Laser mice are more accurate than LED mice, but reviewers say the difference is slight. Laser mice can work on pretty much any surface (except mirrors), including glossy or black surfaces. Glass desktops, however, can trip up most mice, the exception being Logitech's Anywhere Mouse MX, which features the company's Darkfield laser technology that enables it to track on almost any surface including glass. This technology even detects dust and other particles to help it track accurately. The potential advantage of a laser mouse is increased sensitivity -- meaning it can track smaller movements. This is expressed in dots per inch (dpi). While most optical mice can track between 400 dpi and 800 dpi, a laser mouse can track up to 6,000-plus dpi.
Reviews say that sensitivity greater than 800 dpi is only beneficial for gamers, especially those who enjoy first-person shooter (FPS) games, as well as graphic artists, 3D designers and CAD professionals who want the mouse pointer to register the smallest movements of their hand. However, users should be aware that increased sensitivity means that the mouse moves faster with smaller hand movements. For office applications and web surfing, such sensitivity can be frustrating because the mouse pointer will move with even the smallest twitch of your hand. While reviews agree that a high-resolution laser gaming mouse is overkill for general-purpose use, most gaming mice are adjustable, so you can dial down the sensitivity when you're not playing games or doing precise work in Photoshop.
Along with choosing between a gaming and general-purpose mouse, you must decide between corded and wireless. A wireless mouse comes with a radio-frequency (RF) or Bluetooth receiver, which plugs into a USB port on your computer. The transmitter in the mouse then communicates wirelessly to the receiver. A few mice, notably the Apple Magic Mouse, don't come with a receiver at all because Apple assumes you will be using it with a Bluetooth-equipped Mac.
While going cordless can be a boon for smooth, fast mouse movement, a wireless mouse needs batteries, though some are rechargeable. Reviewers say that in better mice, wireless performance is now as fast as with corded mice, although some gamers remain fans of the corded variety. Wireless mice are typically $15 to $30 more expensive, plus the ongoing cost of batteries for nonrechargeable mice.
A variety of mouse alternatives have faded in popularity. Touchpads (as found on most laptops), stylus-based graphics pads, digital pens and trackballs each have fans for specific reasons. Trackballs are the most popular of those, but they command a minuscule market share and don't get many professional reviews. A trackball is essentially an upside-down old-fashioned mouse with a mechanical ball on top. Instead of moving the mouse on desktop or mouse pad, you use your thumb, palm or fingers to control the cursor. The trackball mainly appeals to those seeking to prevent or alleviate repetitive stress injuries as well as those who work in space-constrained areas. However, trackballs have a major catch: multiple reviewers say that adjusting to one takes weeks, and even then, some people never take to them.
Reviewers say the following about shopping for a mouse:
Manufacturers frequently bundle keyboard and mouse sets as desktop sets. As these sets usually include keyboards and mice that are also sold separately, we cover the separate products in our reports on keyboards.