Unrelieved abnormally high intraocular pressure causes visual impairment. Glaucoma is caused by two types of blockages. (1) The obstruction might arise in the porous tissue between the anterior chamber and the Schlemm canal, the canal itself, or the aqueous veins. This type of blockage is called a trabecular meshwork occlusion. It can be hard or soft, but it always needs to be removed to restore proper flow-through of the eye. (2) A second type of blockade occurs within the fluid of the eye. This type of obstruction is usually caused by debris that has accumulated over time. This debris can include cellular waste products from around healthy eyes cells, protein fragments that can't be eliminated by regular washing, and even small particles of glass or plastic. The debris blocks some of the fluid from flowing out of the eye. As more fluid builds up behind the blockage, this excess fluid pushes on the lens or cornea. This can lead to pain, vision problems, and eventually blindness. To prevent further damage, you need to remove the debris causing the blockage so that fluid can flow through the eye again. Glaucoma remains undetected until it's too late because its symptoms are similar to those of other diseases that do not require treatment.