| International Iridology Institute | ★★★★★ | USA | English, Spanish | Ellen Tart-Jensen | 1979 | Basic, Advanced, Master, Instructor | 12-24 months | 2,800-5,500 | Comprehensive, practical, respected |
| European Institute of Iridology | ★★★★☆ | Germany | German, English | Josef Angerer | 1984 | Foundation, Professional, Advanced | 18-30 months | 3,200-6,200 | Rigorous, systematic, thorough |
| China Iridology Research Center | ★★★★☆ | China | Mandarin, English | Li Wei-Bing | 1992 | Basic, Intermediate, Advanced | 12-18 months | 1,800-3,800 | Practical, TCM integration, comprehensive |
| Australian College of Natural Health | ★★★★☆ | Australia | English | Toni Miller | 1990 | Certificate, Diploma, Advanced Diploma | 12-24 months | 3,000-5,800 | Integrative, practice-oriented, professional |
| British Institute of Iridology | ★★★★☆ | UK | English | John Andrews | 1982 | Foundation, Practitioner, Advanced | 18-24 months | 2,700-5,000 | Traditional, authoritative, systematic |
| Canadian Institute of Iridology | ★★★★☆ | Canada | English, French | Robert Morse | 1995 | Basic, Advanced, Master | 12-18 months | 2,400-4,800 | Integrative, nutrition-focused, practical |
| Indian Ayurvedic Iridology Academy | ★★★★☆ | India | English, Hindi | Farida Sharan | 1997 | Basic, Intermediate, Advanced | 12-24 months | 1,400-3,200 | Traditional, integrative, practical |
| Brazilian Natural Medicine College | ★★★★☆ | Brazil | Portuguese, Spanish | Gustavo Ferreira | 1999 | Basic, Professional, Instructor | 12-18 months | 1,700-3,500 | Practical, localized, integrative |
| Japan Iridology Association | ★★★★☆ | Japan | Japanese, English | Akira Nakamura | 1994 | Basic, Intermediate, Advanced | 12-24 months | 2,200-4,200 | Precise, systematic, integrative |
| French Institute of Iridology | ★★★★☆ | France | French, English | Pierre Fragnay | 1992 | Basic, Professional, Advanced | 18-24 months | 2,700-5,200 | Traditional, herbal integration, professional |
| Swiss Academy of Iridology | ★★★★★ | Switzerland | German, French, English | Hans Mueller | 1987 | Basic, Professional, Expert, Instructor | 24-36 months | 4,200-8,500 | Precise, high-standard, authoritative |
| Russian Natural Medicine Academy | ★★★★☆ | Russia | Russian, English | Mikhail Larin | 1998 | Basic, Intermediate, Advanced | 12-24 months | 1,700-3,800 | Traditional, systematic, practical |
| South African Natural Health College | ★★★★☆ | South Africa | English, Afrikaans | Elizabeth van der Merwe | 2002 | Basic, Professional, Advanced | 12-18 months | 2,000-3,800 | Integrative, traditional, practical |
| Spanish Iridology Institute | ★★★★☆ | Spain | Spanish, English | Javier Griso | 1993 | Basic, Intermediate, Advanced | 12-24 months | 2,200-4,200 | Clinical-oriented, professional, systematic |
| New Zealand College of Naturopathy | ★★★★☆ | New Zealand | English, Maori | Sarah Wilson | 1996 | Certificate, Diploma, Advanced Diploma | 12-24 months | 2,700-5,000 | Integrative, natural, professional |
| Italian Association of Iridology | ★★★★☆ | Italy | Italian, English | Daniele Lo Rito | 1989 | Basic, Professional, Instructor | 18-24 months | 2,400-4,800 | Traditional, systematic, professional |
| UAE Integrative Medicine Center | ★★★★☆ | UAE | Arabic, English | Amir Hassan | 2006 | Basic, Intermediate, Advanced | 12-18 months | 3,200-6,500 | Modern, integrative, premium |
| Swedish Natural Health Academy | ★★★★☆ | Sweden | Swedish, English | Nils Jonsson | 1991 | Basic, Professional, Advanced | 18-24 months | 3,000-5,800 | Systematic, scientific, integrative |
| Dutch Iridology Institute | ★★★★☆ | Netherlands | Dutch, English | Olivia van der Meer | 1999 | Basic, Professional, Expert | 12-24 months | 2,700-5,200 | Psychological integration, professional, innovative |
| Mexican Traditional Medicine College | ★★★★☆ | Mexico | Spanish, English | Carmen Rodriguez | 2003 | Basic, Intermediate, Advanced | 12-18 months | 1,700-3,500 | Traditional, integrative, practical |