eye examination is not complete without retinal examination. Sometimes a person may have serious vision threatening problem in spite of 6\6 vision  eg -- diabetic retinopathy, branch vein occlusion, retinal detachment, retinal degeneration and tear etc.

Diabetes & Retinopathy

Diabetic Retinopathy is a disease affecting small blood vessels of the Retina. It has the dual features of vascular leakage and vascular occlusion. 

In diabetes, retinal small vessels undergo certain  changes resulting into weakening of blood vessel wall. This causes

leakage, retinal edema and hemorrhages in retina and vitreous.

usually it takes 10 to 30 years to develop diabetic changes in eye since the onset of diabetese.

good controll of diabetes along with blood pressure [ if it is present] can slow down the eye changes but can not prevent diabetic retinopathy. poor control of diabetes will certainly accelerate the retinopathy.

Other factors which may accelerate the onset of retinopathy-

Pregnancy, anemia, systemic hypertension, renal disease.

Treatment-

annual routine check up - if there is no diabetic retinopathy or no problem in eyes or called by your doctor

early check up if advised by your doctor

when required fundus photograph or FFA [fundus fluorecein angiography ] is done . If indicated , diabetic retinopathy is treated by laser or vitrectomy. Laser treatment may be required many times.

Now this is a very common cause of blindness.