* The retina consists of two types of photoreceptors, cones and rods surrounding the retina, and in the case of retinitis pigmentosa, the photoreceptors lose their ability to function properly.  Often, the defect starts with rods, which causes loss of peripheral and night vision in his eyes, followed by loss of the ability to see colors and central vision when conical cells are affected.

 * Diabetic Retinopathy As the name suggests, diabetic retinopathy is a complication of diabetes, which is the first cause of vision loss in the United States of America, as it causes damage to the blood vessels in the retinal tissue, which leads to fluid leakage from them  And thus disturbance of vision,

 Non-proliferative diabetic retinopathy, which is the least severe form of the disease, and is usually not accompanied by any symptoms.  Proliferative diabetic retinopathy, which is a very advanced condition in which abnormal new blood vessels form in the retina.  Retinal spot hole In the middle of the retina is an area known as the macula, which is responsible for central vision, and seeing the fine details that a person needs during reading, for example,

 * A small gap may arise in it known as the macular hole in the retinal spot. At first, this hole causes blurry vision, and straight lines may appear wavy, and small lines are difficult to read, and with the development of the problem, the patient begins to see a black spot in the middle of his vision, but  This problem does not cause total vision loss, and it is treatable.

 * Retinal tear: The tear arises as a result of shrinking the transparent material in the center of the eye known as the vitreous, which leads to an increase in tension in the retina, and the tissue breaks, causing several sudden symptoms including seeing floating objects and flashing lights.

 * Retinal detachment: This refers to the accumulation of fluid behind the retina, which isolates it from the layers of tissue below it.  Epiretinal membrane, which is a wrinkled, scar tissue-like membrane overlying the retina, causing jagged vision or fog.