The human cornea borders with the sclera via the corneal limbus. Complications of surgical procedures are possible suture erosion through the sclera, conjunctiva, or both. Follicles may also appear at the junction of the cornea and the sclera (limbal follicles). Immune-mediated eye disease can cause ulcers at the border of the cornea and sclera. The collagen of the sclera is continuous with the cornea. Each lens has an individual cornea which extended into a rather large sclera. The cornea, unlike the sclera, has five layers. Similar nodules may be seen on the sclera and eyelids. Typically, there is no uveitis, or thickening of the sclera. The doctor makes a tiny incision in the sclera, or white of the eye. The human eye is relatively rare for having a pale sclera (relative to the iris). The irises of its eyes are white and bordered by bright red sclera. Yellowing of the sclera is a visual symptom of jaundice. Inflammation may also involve the white part of the eye (sclera), a condition called episcleritis. A blue coloration of the sclera may also be symptomatic of disease.