Interlabs Trial Lens Sets is suitable for examining refractive errors, such as myopia, hyperopic, astigmatism, presbyopia also for examination of strabismus & color blindness. It is essential for ophthalmology protection departments in hospitals, the health care departments in factories, schools and country areas, the refraction rooms in glasses shops, and for physicalexamination of soldiers and farmers FeaturesHigh quality Interlabs Trial Lens Set.Lens power indicator clearly imprinted on each lens rim.Lightweight, aluminum rims are color-coded for quick, easy identification of lens power, prismatic power and other information.Supplied with a compact, easy-to-carry lens storage case.Trial Lens Set in Aluminum Case IBL- 21.010Trial Lens Set in Leather Case IBL- 21.020Trial Lens Set in Wooden Case IBL- 21.030Trial Lens Set in Red Leather Case IBL- 21.040266 Trial Lens Set in Wooden case IBL- 21.100266 Trial Lens Set in Leather case IBL- 21.200