👉 Sightlessness is a medical condition where an individual's eyes are unable to focus on objects clearly, causing them to experience blurred vision. This can occur due to several factors such as cataracts, glaucoma, or other eye diseases, which can cause temporary loss of vision in one or both eyes. The most common type of sightlessness is called primary visual impairment (PVI), which occurs when the patient has a complete lack of vision in either eye.