Figure 3: Various corneal pathologies have been captured using C-BLU filter and the corresponding corneal stain positive areas can be seen clearly. (A) Large epithelial defect due to firecracker. (B) limbal nodule preventing complete lid closure leading to inferior corneal exposure keratopathy. (C) Corneal laceration in superior cornea due to pencil stick injury. (D) Severe corneal ulcer and surrounding infiltrates.