Blind capoeira teacher Joao Kanoa jokes with one of his students after giving classes at his home at the Fallet slum, in Rio de Janeiro March 2, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken March 2, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa performs inside a "roda" (wheel) during a session at the Fallet slum, in Rio de Janeiro May 8, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. REUTERS/Pilar Olivares(BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa ties a knot as he wears his capoeira gear before giving classes at the Fallet slum, in Rio de Janeiro March 2, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken March 2, 2013. REUTERS/Pilar Olivares(BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa (L) plays the berimbau during a session at the Fallet slum, in Rio de Janeiro April 12, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 12, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa performs inside a "roda" (wheel) during a session at the Fallet slum, in Rio de Janeiro April 26, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 26, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa plays the berimbau during a session at the Fallet slum, in Rio de Janeiro April 12, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 12, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa searches around for his things before giving classes at the Fallet slum, in Rio de Janeiro April 12, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 12, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa is guided by his students as he returns home after a session at the Fallet slum, in Rio de Janeiro April 26, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 26, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa (L) gathers with his students after a session outside his home at the Fallet slum, in Rio de Janeiro April 12, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 12, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa reaches for a towel at his home before giving classes, at the Fallet slum in Rio de Janeiro April 12, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. Picture taken April 12, 2013. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY) 

Blind capoeira teacher Joao Kanoa plays with a cat at his home at the Fallet slum, in Rio de Janeiro May 8, 2013. Kanoa says he lost his vision at work seventeen years ago when the change of temperature inside a cold-storage room damaged his retina. REUTERS/Pilar Olivares (BRAZIL - Tags: SOCIETY)