Poison ivy is all green. The stem of poison ivy is brown and cylindrical, while blackberry and raspberry stems can be green, can be squared in cross-section, and can have prickles. Raspberries and blackberries are never truly vines; that is, they do not attach to trees to support their stems.
Occasionally, these blood vessels can burst and led to hemorrhage (bleeding) that appears as a red patch on the white of the eye. In the majority of cases, this type of bleeding (called subconjunctival hemorrhage) occurs without a known cause. Subconjunctival hemorrhage can also result from certain medical conditions including trauma, high blood pressure, eye infections, and bleeding disorders. The straining associated with vomiting, coughing, or sneezing can also sometimes lead to subconjunctival hemorrhage. Stress is not a recognized cause of subconjunctival hemorrhage. The good news is, if you had a conjunctival hemorrhage, these are only cosmetically annoying but go away and do not endanger the vision.
When the blood sugar is high, the blood vessels get damaged, causing localized weak areas. Over time, these weak areas start to protrude out, forming a microaneurism. When an aneurism bursts, blood enters into the vitreous, causing a vitreous hemorrhage. Abnormal vessels that grow in response to low oxygen levels in retinal vascular conditions (proliferative diabetic retinopathy, vein occlusions, etc) are very fragile and tend to leak. Sometimes these abnormal vessels grow from the retina into the vitreous cavity and leak blood, causing a vitreous hemorrhage. Mechanical damage to the blood vessels of the retina can occur from a retinal tear or trauma to the eye. Like any other part of the body, if a blood vessel gets damaged, it will start to bleed.