C1 to C10=Clinical isolates of Aspergillus flavus (from patients with keratitis); E1 to E10=Environmental isolates of Aspergillus flavus (from farming areas). The asterisk indicates detected by screening culture filtrates & mycelial homogenates on thin layer chromatography plates. the double asterisk indicates aflatoxin concentration in parts per billion (ppb). The sharp (hash mark) indicates sclerotia size(diameter) >400 µm. The double sharp indicates detected by direct visual examination Statistical analysis (χ² test [Pearson's]; degree of freedom=1). a) Aflatoxin detected in 16 /20 samples from clinical strains versus 8/20 samples from environmental strains; χ²=6.667; p=0.0098. b) % of clinical versus % of environmental strains forming sclerotia in culture: χ²=5.051 (p=0.0246). c) % of aflatoxin-producing versus % of aflatoxin-nonproducing strains forming sclerotia in culture: χ²=10.909 (p=0.0009). d) % of clinical versus % of environmental strains forming a beige ring in culture χ²=0.833 (p=0.3613). e) % of aflatoxin-producing versus % of aflatoxin- nonproducing strains forming a beige ring in culture: χ²=12.535 (p=0.0003).