lithops: any plant of the genus Lithops native to Africa having solitary yellow or white flowers and thick leaves that resemble stones
succulent: a plant adapted to arid conditions and characterized by fleshy water-storing tissues that act as water reservoirs
slit lamp: (ophthalmology) a lamp that emits a narrow but intense beam of light that enables an ophthalmologist, using a microscope, to view the retina and optic nerve