Castor oil sounds like the kind of homespun cure-all your grandmother may have in the back of her medicine cabinet alongside mysterious outdated tinctures and a jar of milk of magnesia. So, you might not think to apply it directly to your eyelids. But that’s exactly what new research out of New Zealand is suggesting for some patients.

According to researchers, blepharitis patients who were treated with topical castor oil showed significant improvements in both ocular surface signs and symptoms. The team reviewed the cases of 26 blepharitis patients—14 females and 12 males, with a mean age of 38 years. The patients were issued a 100% cold-pressed castor oil formulation and instructed to apply it to the lids of only one eye, twice daily for four weeks.

The ocular surface characteristics, symptoms and tear film parameters were assessed at baseline and after 28 days of castor oil on the same eye as well as on their untreated eye, which acted as the control. While the baseline measurements were the same between the treated and control eyes, the patient’s Ocular Surface Disease Index symptomology score was significantly reduced after the four-week treatment period. However, clinical improvements were noted only in the treated eyes. These improvements were seen specifically in eyelid margin thickening, telangiectasia, eyelash matting, madarosis, cylindrical dandruff and lid wiper epitheliopathy. Treated eyes also had greater decreases in staphylococcal and seborrheic eyelash crusting than the untreated control eyes. No adverse events were reported.