Yellowish-white dots on the upper lid are one of the symptoms of trachoma, which is an aggregation of confined lymphocytes in the subepithelial tissue of the conjunctiva on the basis of a diffuse infiltrate. Initially, scattered, meticulous yellow-white dots appear on the upper lid conjunctiva. The incubation period is 5 to 14 days and the disease is bilateral, occurring mostly in children or at a young age. Mild cases of trachoma can have no conscious symptoms at all or only a mild tingling, foreign body sensation and a small amount of discharge. In severe cases, due to sequelae and complications involving the cornea, there are irritating symptoms such as photophobia, lacrimation, pain, and a loss of conscious vision. Chlamydia trachomatis mainly invades the lid conjunctiva and ends with scar formation. The features on examination are as follows: 1. Blood and vascular blurring: due to vasodilatation, there is a diffuse infiltration of chronic inflammatory cells such as lymphocytes and plasma cells under the conjunctival epithelium, making the transparent conjunctiva cloudy and hypertrophic, with unclear vascular contours and a blurred congested appearance. 2. Papillary hypertrophy: the lid conjunctival surface is rough and uneven, showing numerous thread-like dots, which are made by the proliferation of dilated capillary network and epithelium. 3. Filtering hyperplasia: It is an aggregation of confined lymphocytes on the basis of diffuse infiltration of the subepithelial tissue of the conjunctiva. In the first episode, scattered meticulous yellow-white dots appear in the upper lid conjunctiva, not protruding from the conjunctival surface and interspersed between hypertrophic papillae, which is one of the early diagnostic bases of trachoma. 4. Corneal vascular opacification: While the conjunctival lesion occurs, firstly, the vascular network of the semilunar gray area at the upper edge of the cornea is congested and neovascularization occurs, reaching between the transparent corneal epithelium and the anterior elastic layer, accompanied by gray-white dotted infiltration between each neovascularization, which is a tissue reaction of the corneal epithelium to Chlamydia trachomatis, called corneal vascular opacification. It is one of the bases for early diagnosis of trachoma. As the disease progresses, the opacities dangle in rows toward the pupil area, resembling a drape. When the opacities above cross the pupil area, the opacities grow in the other directions of the cornea and proceed to the center, covering the entire cornea. When cellular infiltration is severe, a thick flesh-like opacity can be formed, seriously affecting vision. 5, scar formation: When trachoma proceeds for several years or even decades, all inflammatory lesions such as follicles and papillae will break down or necrosis will occur and gradually be replaced by connective tissue, forming a scar, which marks the lesion has entered the degenerative phase. The course of trachoma varies depending on the severity of the infection and whether the infection is recurrent. In mild cases or those without recurrent infections, the disease can heal in a few months, leaving a thin scar or no visible scar on the conjunctiva. In cases of recurrent infection, the course of the disease can last for several years to decades. The incubation period is about 5 to 12 days. It usually affects both eyes. It mostly occurs in children and adolescents.