Disturbed or Impaired Vision

Disturbed or impaired vision might include blurred vision or seeing double. You may also see flashing lights or floating spots. Visual disturbances may be caused by a problem in one or both eyes or by damage to the areas in the brain that process visual information. If your vision deteriorates suddenly, you should consult your doctor immediately.

  • Do you have pain in the affected eye?

    • Pain
    • No pain

      How long has your vision been disturbed or impaired?

      • Less than 24 hours

        Have you injured your head in the past 48 hours?

        • Recent head injury
          • Possible cause You may have damaged the part of the brain that is responsible for vision (see Head injuries).

            Medical help EMERGENCY! Dial 999/112 and ask for an ambulance, or go to hospital immediately.

        • No head injury

          What is the nature of your disturbed or impaired vision?

          • Sudden loss of all or part of the vision in one or both eyes
            • Possible cause Blockage of a blood vessel that supplies the brain or eye or a serious eye condition such as retinal detachment are possible causes.

              Medical help EMERGENCY! Dial 999/112 and ask for an ambulance.

          • Blurred vision
            • Possible cause Blockage of a blood vessel that supplies the brain or eye or a serious eye condition such as retinal detachment are possible causes.

              Medical help EMERGENCY! Dial 999/112 and ask for an ambulance.

          • Seeing flashing lights or floating spots
            • Possible cause Migraine is a possible cause of recurrent headaches with visual disturbance, but urgent medical assessment is needed to rule out a more serious condition.

              Medical help URGENT! Phone your doctor immediately!

          • Double vision
            • Possible cause This may be due to bleeding inside the brain (see Stroke, and Subarachnoid haemorrhage). It may also be due to an abnormality in the muscles moving the eyes (see Double vision).

              Medical help EMERGENCY! Dial 999/112 and ask for an ambulance.

          • None of the above
            • If you cannot identify a possible cause for your disturbed or impaired vision from this chart, phone your doctor immediately.

      • 24 hours or longer

        Do you have diabetes?

        • Yes
          • Possible cause Diabetic retinopathy or a high blood sugar level can lead to blurred vision.

            Medical help See your doctor within 24 hours.

        • No

          How old are you?

          • 50 or over

            What kind of visual disturbance or impairment have you been experiencing?

            • Blurred vision
              • Possible cause A cataract can cause blurred vision in older people.

                Medical help Make an appointment to see your doctor.

            • Increasing difficulty in focusing on nearby objects
              • Possible cause You may be developing presbyopia as part of the normal aging process.

                Medical help Make an appointment to see your optician.

            • Other disturbance

              Are you currently taking any medications, complementary remedies, or recreational drugs?

              • Yes
                • Possible cause Your symptoms may be a side effect of the medication, remedy, or recreational drug.

                  Medical help See your doctor within 24 hours. Continue to take prescribed medication unless advised to stop by your doctor but stop taking any other medications, complementary remedies, or recreational drugs.

              • No
                • If you cannot identify a possible cause for your disturbed or impaired vision from this chart, see your doctor within 24 hours.

          • Under 50

            Are you currently taking any medications, complementary remedies, or recreational drugs?

            • Yes
              • Possible cause Your symptoms may be a side effect of the medication, remedy, or recreational drug.

                Medical help See your doctor within 24 hours. Continue to take prescribed medication unless advised to stop by your doctor but stop taking any other medications, complementary remedies, or recreational drugs.

            • No
              • If you cannot identify a possible cause for your disturbed or impaired vision from this chart, see your doctor within 24 hours.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.

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