1 In certain unicellular algae, an organelle consisting of closely packed lipid globules (usually or always containing orange or red carotenoids); it is generally believed to be involved in phototaxis.
2 A disease of cereals caused by the fungus Pseudocercosporella herpotrichoides. Initially a dark smudge appears on the outer leaf-sheath, then an oval ‘eye-shaped’ lesion develops near the base of the plant, weakening the stem and leading to increasing susceptibility to lodging (i.e. being laid flat by weather). A similar disease, called sharp eyespot, is caused by Rhizoctonia solari.