Eye-tracking optical device, system, and virtual reality apparatus

An eyeball tracking optical device, comprising:

• a light source assembly, a lens assembly and an image collection assembly, wherein,
• the lens assembly comprises at least one cemented lens, the cemented lens comprises a first lens portion and a second lens portion, a side surface, away from an eyeball, of the first lens portion is provided with a concave surface, a side surface, close to the eyeball, of the second lens portion is provided with a convex surface, the concave surface is attached to the convex surface to form a cemented surface, the cemented surface is provided with a first reflective layer, and a portion, close to the image collection assembly, of the cemented lens is provided with a first plane having an included angle with a focal plane of the cemented lens;
• and
• the light source assembly is configured to emit a first light ray to the eyeball, the first reflective layer is configured to reflect a reflected light ray of the first light ray so as to form a light ray to be imaged, the light ray to be imaged enters the image collection assembly from the first plane, and the image collection assembly collects the light ray to be imaged so as to track the eyeball.