When starting to code with VEXcode V5, Vision Sensor blocks will not appear in the Toolbox until the Vision Sensor has been added as a device and configured.
Adding the Vision Sensor as a Device
Add the Vision Sensor as a device, select the Devices icon.
Select Add a device.
Select the Vision Sensor.
Select which port the Vision Sensor is attached to on the VEX V5 Brain. Ports that are already configured for other devices will be unavailable.
The Vision Sensor configuration window will appear. For steps on how to configure the Vision Sensor, go here.