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Photography obtained by electron microscopy of microvilli of rabbit eye conjunctival epithelium related to samples of (a) Grade 1 (3000–1500 microvilli); (b) Grade 2 (1500–500 microvilli); (c) Grade 3 (500–100 microvilli); (d) Grade 4 (100–0 microvilli); (magnification ×7500).
