Screen resolution
Resolution of built-in displays in glasses equipped with such equipment — that is, models for PC / consoles, as well as standalone devices (see "Intended use").
The higher the resolution, the more smooth and detailed the “picture” is given out by glasses, all other things being equal. Thanks to the development of technology nowadays, models with Full HD (1920x1080) screens and even higher resolutions are not uncommon. On the other hand, this parameter significantly affects the cost of points. In addition, it is worth remembering that in order to fully work with high-resolution displays, you need powerful graphics capable of playing relevant content. In the case of glasses for PCs and set-top boxes, this puts forward corresponding requirements for external devices, and in standalone models you have to use advanced integrated video adapters (which affects the cost even more).
Field of view
The viewing angle provided by virtual reality glasses is the angular size of the space that falls into the user's field of view. Usually, the characteristics indicate the size of this space horizontally; however, if you need the most accurate information, this point needs to be specified separately.
The wider the viewing angle — the more the game space the user can see without turning his head, the more powerful the immersion effect and the less likely that the image will be subject to the "tunnel vision" effect. On the other hand, making the field of view too wide also does not make sense, given the characteristics of the human eye. In general, a
large viewing angle is considered to be an angle of 100° or more. On the other hand, there are models where this indicator is 30° or even less — these are, usually, specific devices (for example, drone piloting glasses and augmented reality glasses), where such characteristics are quite justified given the overall functionality.
Refresh rate
The refresh rate supported by the glasses' built-in screens, in simple terms, is the maximum frame rate that the screens are capable of delivering.
Recall that screens are provided in models for PC / consoles and in stand-alone devices (see "Intended use"). And the quality of the picture directly depends on this indicator: other things being equal, a
higher frame rate provides a smoother image, without jerks and with good detail in dynamic scenes. The flip side of these benefits is an increase in price.
It is also worth considering that in some cases the actual frame rate will not be limited by the capabilities of the glasses, but by the characteristics of the external device or the properties of the content being played. For example, a relatively weak PC graphics card may not be able to pull out a high frame rate signal, or a certain frame rate may be set in the game and not provide boosting. Therefore, you should not chase after large values and
points with a frequency of 90 fps will be enough.
Gyroscope
The presence in the glasses of its own built-in
gyroscope.
The gyroscope captures the direction, speed, and angle of rotation of the device—usually along all three axes. Without such a sensor, it is impossible to achieve a full-fledged "immersion" in virtual reality, so it is available in all standalone glasses, as well as in most models for PC / consoles (see "Intended use"). In the second case, the only exceptions are individual models with a specific purpose — "personal cinemas", glasses for piloting drones, etc. In turn, glasses for smartphones do not initially require gyroscopes, since smartphones themselves have such sensors. However, there are exceptions here too — advanced models created for specific top-level devices: in them, the built-in gyroscope works in conjunction with the gyroscope of the connected smartphone, ensuring maximum positioning accuracy.
Proximity sensor
The presence of a
sensor in the glasses that reacts to approaching the user's face.
A similar sensor is used to automatically switch between operating and standby modes: for example, when the user takes off the glasses, the sensor turns off the built-in screens (or the phone, if it is connected to the glasses via a connector), saving battery power and equipment life, and when put on, it turns on points for full functionality.
Lens distance adjusting
The ability
to move the lenses of the glasses back and forth, thus changing their location relative to the screen and the user's eyes. The specific meaning of this function can be different: it can adjust the angle of view (so that the screen fits completely in the field of view and at the same time is not too small), play the role of diopter correction (which is important for users who wear glasses) or focus, change the setting interpupillary distance (see below), etc. These nuances should be clarified separately. However, anyway, this function will not be superfluous — it makes it easier to adjust the glasses to the personal characteristics of the user.
USB C
The presence in the glasses of the connector type
USB-C. This is a relatively new type of USB port, which has a miniature size (slightly larger than microUSB) and a convenient double-sided design that allows you to connect the plug in either direction. It can be found in glasses for various purposes and, accordingly, provide different ways of application. So, in models for PC / consoles, this connector is used similarly to traditional USB — with the main connection, in parallel with the HDMI or DisplayPort video interface. In standalone devices, on the other hand, USB-C is mainly used to charge the battery and connect to a computer for direct file exchange, settings management, firmware updates, etc.
Also note that this paragraph may specify the USB version, which corresponds to the USB-C connector. Nowadays, two versions are relevant — 3.2 gen 1 and 3.2 gen 2; for VR glasses, the difference between them is generally not fundamental.
Bluetooth
The presence of a
Bluetooth module in the glasses; The Bluetooth version to which this module corresponds can also be specified here.
Bluetooth is a technology created for direct wireless connection between various devices. This technology is found in all types of VR glasses (see “Purpose”), although most models with its support are independent devices. In any case, the most popular way to use Bluetooth in virtual reality glasses is to broadcast sound wirelessly. Moreover, the format of such a broadcast may be different, depending on the specifics of the glasses themselves. Thus, standalone devices broadcast the reproduced sound to external headphones. Models for PCs and smartphones may have built-in headphones, and here the sound is transmitted via Bluetooth to the glasses from an external device; Audio from the built-in microphone can be transmitted in the opposite direction.
In addition, there are other possible ways to use Bluetooth, such as directly exchanging files with another device or connecting game controllers. Such capabilities are found exclusively in stand-alone glasses; the specific functionality for each model should be clarified separately.
As for the versions, the oldest one used in VR glasses today is Bluetooth 3.0, the newest is Bluetooth 5.0. However, the differences between different versions for such devices are not fundamental; this information is provided mainly for reference purposes.
Wi-Fi
The Wi-Fi version supported by the glasses.
Wi-Fi technology is known mainly as the most popular way to connect to the Internet wirelessly, although it can also be used for direct connection between different devices (Wi-Fi Direct). Anyway, this function is found exclusively in stand-alone devices (see "Intended Use"). It is mainly used to connect to the World Wide Web, but the possibilities of such a connection may be different. So, in some models, a Wi-Fi connection is used to access proprietary application repositories, cloud services for storing game data, etc. Others may provide support for third-party services such as social networks or instant messengers, or even a full-fledged browser for web surfing. Technically, nothing prevents the use of Wi-Fi Direct in VR glasses, but for a number of reasons, this format of work is almost never found.
As for the versions, in modern virtual reality glasses there are mainly Wi-Fi 4 (802.11 n) and Wi-Fi 5 (802.11 ac). The difference between them in most cases is not fundamental, especially since, for compatibility, Wi-Fi modules often provide support for not only one of these standards, but also earlier ones. And the new Wi-Fi 6 at the beginning of 2021 has not yet gained much popularity. But everything has its time.
