Abstract: A gonioscopy lens is a contact lens that is used to observe and assess the anterior chamber angle (ACA) of the eye. A gonioscopy assembly (100) advantageously includes a gonioscopy lens adapted for connection to a tonometer. The gonioscopy assembly includes an eye contact portion (41) which is positioned in contact with the eye by moving the tonometer, which also holds the gonioscopy assembly in place to maintain it in contact with the eye. When the gonioscopy assembly is provided with one or more mirrors, all four quadrants of the ACA may be viewed simultaneously, without repositioning the slit lamp or the gonioscopy assembly (100). For increased convenience, stability and precision, the tonometer may optionally form part of the tonometer arm of a slit lamp.