a, Representative H&E images of the stratified corneal epithelium (top) and the keratocyte-laden stroma (bottom). Scale bars, 20 μm. This experiment was replicated three times. b, Immunofluorescence staining of p63 in the stratified corneal epithelial cells. The dotted line indicates the boundary between the epithelium and the stroma. Green, p63; blue, DAPI. Scale bar, 15 μm. This experiment was replicated twice. c, Representative image of occludin in the differentiated corneal epithelium. The cells were imaged by immunofluorescence staining in three independent experiments. Green, occludin. Scale bar, 100 μm. d, Scanning electron micrographs of microvilli (top row) and microplicae (bottom row) on the surface of the differentiated corneal epithelium in our model (left column) and in the human eye (right column). Scale bar, 1 μm. Images were obtained from three engineered eye devices and two human cornea samples. e, Immunofluorescence images of CK-3/12 expression in the corneal epithelial cells. SUB represents the submerged group. ALI was initiated on day 2. Images were acquired from four independent experiments. Red, CK-3/12; blue, DAPI. Scale bar, 20 μm. Quantified data show mean fluorescence intensity (MFI) normalized to the day 2 group. Error bars indicate s.e.m. P values by unpaired, two-sided t-test. f, Representative H&E image of the stratified conjunctival epithelial cells. This experiment was replicated three times. Scale bar, 20 μm. g,h, Immunofluorescence micrographs of CK-19 (g) and MUC16 (h) expressed by the conjunctival epithelial cells. Green, CK-19; red, MUC16; blue, DAPI. Scale bars, 20 μm. The images are representatives of two independent experiments. i, Representative images from AB-PAS staining of the engineered ocular surface. ALI was initiated on day 2. SUB represents the submerged group. Data represent mean ± s.e.m. of staining intensity normalized to the Acellular group from three independent experiments. P values by unpaired, two-sided t-test. j, Scanning electron micrograph showing a network of nanofilaments (shown with yellow arrows) on the engineered ocular surface. Scale bar, 1 μm. This experiment was replicated three times. a.u., arbitrary unit.