Terrien’s marginal degeneration is a peripheral corneal thinning disorder which results in loss of corneal shape and poor vision over time. It is typified by the presence of lipid deposits in the periphery and corneal vascularisation.Occasionally, it can be associated with symptoms of redness, pain and inflammation – as in this 35 year old lady. There is no known effective treatment for this condition and the importance of recognising the diagnosis is to help avoid unnecessary investigations and potentially dangerous treatment side effects.