Either of these symptoms can occur.

Eye disorders

• benefits black dots in the visual field, or areas without vision.
• Poor color perception and poor vision in the dark.
• A drought eyes.
• A sight tangled.
• Loss of visual acuity, which can go as far as blindness. Usually, the loss is gradual.

Sometimes there is no symptoms. See an ophthalmologist regularly.

Neuropathy (affections to the nerves)

• A decrease in sensitivity to pain, heat and cold in the extremities.
• Tingling and burning sensation.
• Erectile dysfunction.
• Slowing of stomach emptying, causing bloating and regurgitation after a meal.
• Alternating diarrhea and constipation if the nerves in the intestine are affected.
• The bladder that does not empty completely or sometimes from urinary incontinence.
• Postural hypotension, which manifests as dizziness on passing from lying down to standing, and which can cause falls in older people.

Susceptibility to infections

• Various infections: of the skin (especially on the feet), gums, respiratory tract, vagina, bladder, vulva, foreskin, etc.

Nephropathy (kidney problems)

• Hypertension sometimes announces the onset of kidney damage.
• The presence of albumin in the urine, detected by a laboratory test (normally urine is free of albumin).

Cardiovascular illnesses

• Slow healing.
• Chest pain during exertion (angina pectoris).
• Calf pain that interferes with walking (intermittent claudication). These pains disappear after a few minutes of rest.