Redness in the eye after eyelash extensions is most likely caused by an allergic reaction. There is also the possibility of inflammation. 1. Allergic reaction: redness of the eyeball after eyelash extensions, first of all, consider the emergence of allergic reaction, you can stop eyelash extensions. You can stop the extensions and remove the eyelashes if necessary, and the symptoms can usually be improved by keeping them away from the allergens; you can also take allergy medications such as loratadine orally to alleviate the symptoms. 2. Inflammation and infection: there may also be inflammation caused by bacterial infection, you can let the use of erythromycin ophthalmic solution coated with its own eyeball, can be very good to improve the symptoms. Eyelash extensions after the eyeball red may also be other reasons, please go to the local hospital ophthalmology consulting consultation, listen to the professional doctor’s advice, choose a reasonable way of treatment, the above drugs need to be standardized under the guidance of the doctor to use.