If you find that infants and young children are prone to crying, photophobia, tearing, and eyelid spasms, be alert to a blinding eye disease; congenital glaucoma. These children generally have large, dark, unlit eyes with poor vision or blurred vision; because the connective tissue of the eye is more elastic in infancy, it has many unique signs and symptoms compared to glaucoma in adolescents or adults. It is very important for doctors and parents to master and recognize the signs and symptoms of glaucoma in infancy and early childhood to detect and diagnose this disease in time. Currently, the incidence of primary congenital glaucoma in the general population is 1:10,000, with primary congenital glaucoma being the most common among infantile glaucoma. The incidence is significantly higher in males than in females, accounting for approximately 65% of the total number of primary congenital glaucoma patients. 75% of primary congenital glaucoma patients develop the disease in both eyes simultaneously or sequentially. Although the time of onset of primary congenital glaucoma is not identical, more than 80% develop within the first year of life. Most patients with primary congenital glaucoma have a single onset. The pathogenesis of primary congenital glaucoma is due to obstruction of the anterior chamber angle, which originates from neural crest cells and leads to obstruction of atrial outflow by one or more mechanisms; high attachment of the ciliary body and iris to the trabecular meshwork, causing compression of the meshwork; and abnormal development of different planes of the trabecular meshwork, such as the schlemm’s canal, which may also contribute to the obstruction of atrial outflow that leads to an increase in intraocular pressure. The signs and symptoms of primary congenital glaucoma in infancy are summarized in the following five areas: (1) photophobia and blepharospasm; (2) increased corneal edema and rupture of the posterior elastic lamina; (3) enlarged anterior chamber and axial myopia; the enlargement of the eye occurs mainly before 3 years of age and rarely continues after about 3 to 4 years of age; (4) increased intraocular pressure; (5) atrophy of the optic papilla and (4) Increased sunkenness; C/D > 0.3, asymmetric C/D values in both eyes with a difference of > 0.2 should be suspected of glaucoma. Unless the child’s IOP is controlled to normal levels, photophobic tearing and blepharospasm will persist and will continue to worsen. The presence of these signs and symptoms is not only an important basis for diagnosing glaucoma in infancy, but also helps determine whether the patient’s IOP is normal after glaucoma surgery. If a child is suspected of having congenital glaucoma, several necessary tests should be done: 1) measurement of corneal diameter; 2) anterior chamber angioscopy; 3) measurement of the axial length of the eye; and 4) dilated pupillometry. Therefore, if parents find that their infant or child has large black eyes without light, photophobia, tearing, crying from time to time or apparently cannot see objects in front of them, they should come to the children’s hospital for early and prompt treatment in order to restore or save useful vision.