Ocular myasthenia gravis with rainbow when looking at the light can be considered to be caused by refractive error, glaucoma and other eye diseases, the specific condition can be judged according to the symptoms and examination. 1. Refractive error: common types of refractive error, including astigmatism, myopia and hyperopia, without eyeglasses to correct the situation, there will be blurred vision, when looking at the light there will be a rainbow aperture, the need to wear eyeglasses to correct vision. 2. Glaucoma: more common in the elderly, will be manifested as increased intraocular pressure, blurred vision and corneal edema, etc., looking at the light will appear rainbow aperture. There are many reasons that lead to rainbow aperture when looking at the light of eye-type muscle weakness, and if you can’t determine the cause of the disease, it is recommended that you have a timely examination of the fundus of the eye, the intraocular pressure and other aspects of the examination, and treat it in a reasonable way.