However, it is the environment that impacts their visual function rather than their neurology or capacity for vision at that moment. A persons change in visual function when processing visual information in a complex environment, or trying to process a certain complex or unfamiliar visual target likely accounts for what looks like their visual ability changing from one day to the next, or from minute to minute. Feeling tired or unwell may also compound this challenge. For some people with CVI the complexity of the environment, including variables like the complexity and familiarity of the visual input, or processing various forms of secondary sensory input (for instance, sound or touch) may cause them to have difficulty using their vision to their full potential. The amount of sensory input an individual can tolerate without impacting function significantly may change throughout development and person to person. Managing fatigue may reduce fluctuations but does not eliminate them, however utilizing breaks and being well rested may help to increase resilience during these times. Addressing these changes may mean adapting strategies that work for the individual person. For example, When undertaking critical activities, people with CVI should be prepared for their vision to fluctuate, by taking precautions such as always carrying a white cane, if they use one, even if they dont always use it to the fullest. Another example is having very large print available, just in case its needed (For example, consider the consequences of losing vision while giving a public speech).
Individuals ages 21–40 years are most commonly affected.A 2002 study looking at 445 samples of dermatophytes in patients in Goiânia, Brazil found the most prevalent type to be Trichophyton rubrum (49.4%), followed by Trichophyton mentagrophytes (30.8%), and Microsporum canis (12.6%).A 2013 study looking at 5,175 samples of Tinea in patients in Tehran, Iran found the most prevalent type to be Tinea pedis (43.4%), followed by Tinea unguium. (21.3%), and Tinea cruris (20.7%). See also
Mycobiota

References
Further reading
Weitzman I, Summerbell RC (1995). "The dermatophytes". Clinical Microbiology Reviews. 8 (2): 240–259. doi:10.1128/cmr.8.2.240. PMC 172857. PMID 7621400. External links

Tinea photo library at Dermnet