The liver

‘gan kai qiao yu mu’ – ‘The liver opens in to the orifice of the eyes’ (2 p38)

In TCM, the eyes are the sense organ relating to the liver. The liver supports our eye health and also governs our capacity for vision in our lives, our sense of direction and the ability to see where we are going and make plans.

Liver blood nourishes the eyes and when liver blood is deficient we may suffer from blurred vision, myopia (short-sightedness), floaters (dots or lines in your vision that move about as you move your eyes), impaired night vision or colour blindness. Accompanying liver blood deficiency signs and symptoms can include dizziness, insomnia (trouble getting to sleep), pallor, light or absent periods, muscle spasms and brittle nails with a pale tongue (especially the sides as these relate to the liver) and a thin radial pulse on palpation. Liver blood can be weakened by poor diet or impaired digestion, bleeding as in haemorrhage, heavy periods or in the postpartum and is an especially common pattern for women.     

The yin energy of the liver also provides nourishment to the eyes. When liver yin is weak, we will see many of the opthalmalogical symptoms above, but also dry eyes which can be a hallmark feature (3). Accompanying symptoms can include nightsweats, tinnitus, insomnia (hard to stay asleep), a red tongue with little or no coat and a rapid, fine pulse. Liver yin can become depleted via ongoing liver blood deficiency and as usually combined with kidney yin deficiency which stems from overwork, chronic illness, excessive sexual activity or exercise, depletion of body fluids from febrile disease or overuse of yang tonics.    

Conditions of excess in the liver also affect the eyes. The liver meridian passes through the eyes on the way to the top of the head. Liver yang (if not anchored by liver yin), heat or fire can rise or flare upwards via this channel leading to glaucoma, a feeling of pressure in the eyes, protruding eyeballs, blurred vision, bloodshot, painful, burning or severely itchy eyes. This will typically present with concurrent irritability, headache, dizziness, red complexion, thirst, dark urine, sleep disturbance, a red tongue (especially the sides) with a yellow coat and a full, rapid pulse. Heat in the liver is often generated by repressed or ongoing anger, frustration or resentment and from overconsumption of heating substances such as alcohol, red meats and fried foods. Constrained emotions also lead to liver blood stagnation which may result in eye pain, strabismus, dark spots on the sclera and be paired with a dark complexion, darkness under the eyes and a purple tongue.  

In TCM we often speak of internally generated ‘wind’. Wind can be described as an energetic pathogen that is moving in nature (think muscle tics, itches, moving pains etc) and fills empty space created by deficiency, often of the blood or yin. It can also be created by yang rising and excessive heat like the kinetic wind force above an open fire. The liver, being prone to blood and yin deficiency, ascendant yang energy and heat, is readily affected by wind and this can manifest in eye conditions such as strabismus, nystagmus, protruding eyeballs and a feeling of distension in the eyes. Accompanying symptoms may include vertigo, tics or tremors, spasms, numbness of the limbs (liver blood deficiency leading to wind) and liver heat signs as above (liver heat turning to wind). A deviated and, or, quivering tongue are also signs of internal wind.

The kidneys

Kidney yin and jing (our inherited, constitutional ‘essence’) also nourish the eyes. Congenital eye conditions such as myopia and strabismus, chronic eye diseases and eye problems in the elderly, especially glaucoma and cataracts, are often due to insufficient or declining Kidney yin or jing.Accompanying symptoms for kidney yin deficiency are similar to, but perhaps more pronounced than, those for liver yin deficiency (indeed, the two pathologies often occur together), but here we will also see signs of general kidney deficiency such as sore low back and knees, poor memory, possible hearing impairment, tinnitus and nocturnal emissions. Deficient kidney jing may also display signs of greater kidney weakness including poor bone development in children, greying hair, hair loss, senility and loose teeth. Puffiness under the eyes is often a sign of kidney weakness. Kidney jing can be a constitutional deficiency or come about from aging or excessive sexual activity.

The heart

The classics state that ‘the spirit and the essence of the heart gather in the eyes’ (3 p77). The state of our spirit (our shen which resides in the heart) shines through our eyes. When the eyes are bright and sparkling, we know that a person is thriving in their emotional, mental and spiritual lives. Observation of the eyes is, therefore, very important in TCM to ascertain the degree of a presenting mental or emotional disturbance but also whether or not the shen has been impacted by or perhaps even stands as the underlying cause of a physiological complaint.

Like liver blood, heart blood also nourishes the eyes and as the heart channel also flows to the eyes, pathologies of the heart can often transfer to them. In particular, to the inner and outer corners of the sclera. If heart blood is deficient these will be pale and paired with symptoms such as diminished visual acuity, blurred vision, a tendency to startle easily, anxiety, insomnia, palpitations and a pale face and tongue. Heart blood becomes deficient via the same mechanisms as liver blood deficiency, but also from prolonged anxiety or worry. Heat in the heart stemming from emotional factors can lead to pain, burning, redness and itching of the eyes, especially the corners as well as typical heart heat signs such as insomnia and vivid dreams , palpitations, ulcers on the tongue, mental restlessness, heat sensations, a red face, bitter taste in the mouth, thirst, a red tongue (especially the tip) with a yellow coat and a rapid pulse.   

Environmental factors

In addition to organ disharmonies, the eyes are also affected by environmental factors. In particular, they are prone to invasion from Wind. This presents with acute symptoms with a sudden onset such as red, intensely itchy, streaming, sticky yellow discharge, swollen eyelids perhaps with a boil are generally from external wind-heat. These will be accompanied by an aversion to cold and a fever. External dryness can lead to dry, itchy, red eyes and dampness can create swelling and mucus.