This is done by using glycosidase enzymes from specific bacteria to strip the blood group antigens from red blood cells. The removal of A and B antigens still does not address the problem of the Rh blood group antigen on the blood cells of Rh positive individuals, and so blood from Rh negative donors must be used. The sort of blood is named "enzyme converted to O" (ECO) blood. Patient trials will be conducted before the method can be relied on in live situations. One such Phase II trial was done on B-to-O blood in 2002.Another approach to the blood antigen problem is the manufacture of artificial blood, which could act as a substitute in emergencies. Pseudoscience
During the 1930s, connecting blood groups to personality types became popular in Japan and other areas of the world. Studies of this association have yet to confirm its existence definitively.Other popular but unsupported ideas include the use of a blood type diet, claims that group A causes severe hangovers, group O is associated with perfect teeth, and those with blood group A2 have the highest IQs. Scientific evidence in support of these concepts is limited at best. See also
Secretor status – secretion of ABO antigens in body fluids

References
Further reading
Dean L (2005). "Chapter 5: The ABO blood group". Blood Groups and Red Cell Antigens. Retrieved 24 March 2007. Farr A (1 April 1979). "Blood group serology--the first four decades (1900–1939)". Med Hist. 23 (2): 215–26. doi:10.1017/s0025727300051383. PMC 1082436. PMID 381816.
Retinal tear accounts for 11.4–44% of vitreous hemorrhage cases. Posterior vitreous detachment
As one gets older, pockets of fluid can develop in the vitreous. When these pockets develop near the back of the eye, the vitreous can pull away from the retina and possibly tear it. Posterior vitreous detachment accounts for 3.7–11.7% of vitreous hemorrhage cases. Other causes
Less common causes of vitreous hemorrhage make up 6.4–18% of cases, and include:

Proliferative sickle cell retinopathy
Macroaneurysms
Age-related macular degeneration
Terson syndrome
Retinal neovascularization as a result of branch or central retinal vein occlusion
Other

Diagnosis
Vitreous hemorrhage is diagnosed by identifying symptoms, examining the eye, and performing tests to identify the cause. Some common tests include:

Examination of the eye with a microscope
Pupil dilation and examination
An ultrasound examination may be used if the doctor does not have a clear view of the back of the eye
Blood tests to check for specific causes such as diabetes
A CT scan to check for injury around the eye
Referral to a retinal specialist

Complications
Ghost cell glaucoma: Secondary open angle glaucoma caused by degenerated red blood cells. Treatments
The treatment method used depends on the cause of the hemorrhage. In most cases, the patient is advised to rest with the head elevated 30–45°, and sometimes to put patches over the eyes to limit movement prior to treatment in order to allow the blood to settle. The patient is also advised to avoid taking medications that cause blood thinning (such as aspirin or similar medications). The goal of the treatment is to fix the cause of the hemorrhage as quickly as possible.