Cell Aggregate Including Retinal Tissue and Production Method Therefor

A sphere-like cell aggregate comprising:

• a core part containing neural retina;
• and
• a covering part continuously or discontinuously covering at least a portion of a surface of the core part, wherein
• (1) in the neural retina, a neural retinal layer including at least a photoreceptor layer is formed, wherein the photoreceptor layer contains one or more types of cells selected from the group consisting of at least a photoreceptor cell, a photoreceptor progenitor cell, and a retinal progenitor cell, and the cells contained in the photoreceptor layer are continuously present in a tangential direction to the surface of the core part;
• (2) the covering part contains retinal pigment epithelial cells in contact with each other;
• (3) the cell aggregate is free of a crystalline lens, a vitreous, a cornea, and a blood vessel;
• and
• (4) the retinal pigment epithelial cells do not constitute an epithelial structure continued with the neural retinal layer.