Reading aids for the partially sighted. A nontechnical explanation of basic optical principles.
D002648:Child; D005139:Eyeglasses; D006225:Hand; D006801:Humans; D007909:Lenses; D009216:Myopia / Q000534:rehabilitation; D055095:Optics and Photonics; D011305:Presbyopia / Q000534:rehabilitation; D011932:Reading; D012030:Refractive Errors / Q000534:rehabilitation*; D012656:Self-Help Devices; D013690:Television