Ophthalmology is the branch of medicines which deals with anatomy, physiology and diseases of the eye. Some of the major eye diseases include haloes, distorted vision, eyelid abnormalities, glaucoma, retinal disease and cataract. The ophthalmology device market is categorized based on various diagnostic and monitoring devices, surgical devices and vision care products. These segments comprise several devices used for treatment of eye diseases. The diagnostic and monitoring device segment is further sub-segmented into fundus cameras, pachymeters, specular microscopes, optical coherence tomography scanners, keratometers, ophthalmic ultrasound imaging systems, wavefront aberrometers, tonometers, slit lamps and corneal topographers. The surgical device segment includes refractive device, vitreoretinal surgery device, cataract and glaucoma devices. The vision care segment comprises spectacles and contact lenses.