Tools such as the white cane with a red tip – the international symbol of blindness – may also be used to improve mobility. A long cane is used to extend the users range of touch sensation. It is usually swung in a low sweeping motion, across the intended path of travel, to detect obstacles. However, techniques for cane travel can vary depending on the user and/or the situation. Some visually impaired persons do not carry these kinds of canes, opting instead for the shorter, lighter identification (ID) cane. Still others require a support cane. The choice depends on the individuals vision, motivation, and other factors. A small number of people employ guide dogs to assist in mobility. These dogs are trained to navigate around various obstacles, and to indicate when it becomes necessary to go up or down a step. However, the helpfulness of guide dogs is limited by the inability of dogs to understand complex directions. The human half of the guide dog team does the directing, based upon skills acquired through previous mobility training. In this sense, the handler might be likened to an aircrafts navigator, who must know how to get from one place to another, and the dog to the pilot, who gets them there safely. GPS devices can also be used as a mobility aid. Such software can assist blind people with orientation and navigation, but it is not a replacement for traditional mobility tools such as white canes and guide dogs.
Treatment
Up until the advent of modern therapies, favus was widespread worldwide; prior to Schönleins recognition of it as a fungal disease, it was frequently confused with Hansens disease, better known as leprosy, and affected Europeans were sometimes committed to leprosaria. Today, due to this species high susceptibility to the antifungal drug griseofulvin, it has been eliminated from most parts of the world except rural central Asia and scattered rural areas of Africa. It is mainly a disease connected to demographic poverty and isolation, but is so readily treatable that it is among the diseases most likely to be eliminated by modern medicine. References

This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Favus". Encyclopædia Britannica. Vol. 10 (11th ed.). Cambridge University Press. p. 215. Kane, J., R.C. Summerbell, L. Sigler, S. Krajden, G. Land. 1997. Laboratory Handbook of Dermatophytes: A clinical guide and laboratory manual of dermatophytes and other filamentous fungi from skin, hair and nails. Star Publishers, Belmont, CA. Gräser Y, Kuijpers AF, Presber W, De Hoog GS (October 1999). "Molecular taxonomy of Trichophyton mentagrophytes and T. tonsurans". Med. Mycol. 37 (5 Cpages=315–30): 315–30. doi:10.1046/j.1365-280x.1999.00234.x. PMID 10520156. == External links ==