Hopes a clinical trial will find a longer-term treatment for dry-eye disease

Auckland University researchers are set to run trials using a cold-pressed castor oil enhanced with manuka and kanuka oils, as a safe and natural treatment.

The most common cause of dry-eye disease is blepharitis -- a chronic condition with no known cure.

Principal investigator Professor Jennifer Craig, says current treatments like eye-drops aren't really suitable long-term.

She says eye drops often try to replace the watery part of the tears, when it's important to focus on the lipids -- but drops that do that tend to be more expensive.