Fig. 1From: Measurement of crystalline lens tilt in high myopic eyes before cataract surgery using swept-source optical coherence tomographySchematic diagram of the calculation of lens tilt in the space rectangular coordinate system (O-XYZ). OP is the unit normal vector for the lens plane. OA is the projection of OP on the X–Y plane. Angle ρ is the angle between OP and the Z-axis and represents the magnitude of the lens tilt. Angle φ is the angle between OA and the X-axis, and represents the direction of the lens tilt. X-axis: horizontal axis; Y-axis: vertical axis; Z-axis: visual axisBack to article page