Dry eye syndrome Modern Perspective
Dry Eye Syndrome” is  a  general  term that  describes  the state  of the  front of  the  eye, the tear film. Normally, this layer of tears is stable that not only provides the cornea and conjunctiva a healthy buffer from damage where it is constantly exposed to the air in the office workers, but this interface between the tear  film  and  the  air  is  also  responsible  for  a  significant amount  of  focusing  power  of the  eye. When the  tear  film  becomes  unhealthy,  it  breaks  down  in different places on the cornea and conjunctiva leading not only to symptoms of irritation, but also to unstable and  intermittently  changing  vision. 

Other  symptoms of dry eyes include, burning sensation, itching, tearing, foreign body sensation, frequent blinking, redness, eye pain, eye  fatigue,  blurring  of  vision.

Ayurveda Perspective
In Ayurveda all diseases related to the eye are not restricted to the eyes itself, but are considered as a result of the imbalance state of the Doshas.

Dry Eye has  no  direct  reference  in Ayurveda  classics. However, similar clinical manifestations can  be  observed in  a  disease called Shushkakshipaka. Shushakshipaka is one of the Sarvagata roga as classified by Susruta, which is caused due to the vitiation of vata-pitta doshas.

  • The Shushkashipaka is a disease which is characterized by the paka of akshi (eye) due to sushkata (dryness) caused by altered coherence of Ashru (tears) with ocular surface or lack of ashru. 
  • This disease is also characterized by difficulty in the eyelid movement and blurred vision due to excessive vitiation of Vata. 
  • Karala tantra has identified excessive burning sensation, daha (burning sensation) in sushkapaka (dry eyes).
  • The Suskapaka is defined as a Vataja eye disease producing closure and roughness in eye lids, associated with difficulty in lid movements, blurred vision etc.(Karala tantra quoted by Madhukosha on M.N.59/17). 
  • Bhavapraksha has added ‘Samdahyate’ or burning to the list of symptomatology of Sushruta Samhita.

Lakshanas (Symptoms) 

  • Narrowing of palpebral apearture (Kunita Vartma)
  • The lids are stiff and dry (Daruna ruksha vartma)
  • Difficulty in opening of eyelid and blurred vision (Avila darshna)
  • foreign body sensation (Gharsha)
  • pricking and cutting type of pain (Todan and Bheda)
  • Mucoid type of discharge (Upadeha)
  • Dryness (Vishushkatwa )
  • Liking of cold (Shitecha)
  • Crucifying pain, inflammation (Sulapakatwam)
  • Burning sensation (Daha)

Reference :  (Ashtanaga Hridayam U 15/16, Sushruta.U.6/16)

Samanya Nidana (Similar Etiological factors)

  • Dry eye is caused by Vata vitiating factors
  • Later on, Pita vitiating factors also contribute to the disease pathology. 
  • There are two types of factors to be considered. One is the general vata/pitta vitiating factors and vishesha achakshushya nidanas that affects netra avayava specifically.
  • Samanya Nidanas: Factors which can cause vitiation of vata and pitta are (Vegavinigraha) suppress natural urges causes vata vitiation. Suppression of adhovata, mala (bowels), mutra(urine) and nidravega (controlling sleep) can initiate ocular (eye) pathology.
  • Direct exposure to smoke (Dhoomanishevana). Causes vitiation of pitta dosha by its ushna teekshna (hot and sharp) properties. Also vata dosha is aggravated by its dry (ruksha),light (laghu), Minute (sookshma) qualities
  • Smoking is an aetiological factor for dry eyes.
  • Exposure to dust and smoke (Rajodhumanishevanath- according to Bhavamisra)
  • Frequent travel in speedy vehicles (Atisheegravyanath).
  • Extreme exposure to air conditioned environment (Atisheetha sevanath). This leads to vata prakopa . Scientists have found that colder outside temperatures drive down temperatures on the eye surface and eyelid. The meibum (the oily substance in the outermost layer of the tear film) becomes too thick and too stiff to spread evenly and protect the eye.
  • Hot, dry climate – Vatha Pitha kopa
  • Older age – Vatha prakopa is common in older age. Old age has been recognised as a cause of dry eyes.
  • Intake of food predominantly katu (spicy), kashaya (pungent) and tikta rasa (bitter), dried leafy vegetables, roasted meat, pulses like mudga (green gram), masura (lentil), kalaya (pea).

Vishesha Nidana (Different Etiological factors)
Nidana that are responsible for eye disease are mentioned in detail by Susrutha. Amongst these nidanas, those that lead to dry eyes are:

  • Looking at distant objects for a long time (Doorekshanata). This results in infrequent blinking resulting in decreased secretion from meibomian glands. 
  • Prolonged visual efforts associated with decreased blink rate such as reading or watching TV or altered sleep pattern (Swapna viparyaya). 
  • Night awakening causes vata pitta prakopa .
  • Continuous weeping (Prasakta Samrodana). It causes vata vitiation. It leads to neuro deprivation resulting in less tear secretion.
  • Excessive anger and grief (Kopa and Shoka) also leads to pitta and vata vitiation respectively which affects the tear secretion 
  • Food like shukta (roasted rice powder made into a porridge), amla, and aranala (dehusked wheat) and foods with alcoholic prope.ties, which leads to vatha pitta aggravation.  Kulatha (Horse gram) taken for long time causes raktha and pitta disorders
  • Excessive or minimal usage of Eyes (chakshur indriya) 

When we analyse the etiological factors, signs and symptoms, Sushkashipaka closely resembles Dry eye syndrome in modern ophthalmology. 

In  Ayurveda  classics,  specific  treatment  has  been mentioned for  Shushkakshipaka  such as:

  • Snehapana  (in-take of Ghee) :  Snehapana is done for vata-pitta shaman and dhatu poshana. Intake of old Ghrita is very useful for the ocular tissues. After Pana, the Ghrita gets absorbed into the systemic circulation. Due to Chakshushya properties, it has an affinity towards ocular tissues and due to its lipid soluble property crosses blood ocular barriers.
  • Mridu Virechana : Due to the importance of rakta dushti in pathogenesis, it is better to go for langhana and mridu virechana
  • Tarpana (retention of ghee over eyes): Akshitarpana is a unique procedure where medicated Ghrita is retained over the eyes for a specific amount of time. Tarpana- As Ayurveda texts says, Tarpana gives strength to eyes i.e. it is Dristiprasadaka so used in various diseases.
  • Nasya (Nasal medication): It is a procedure where medicines are administered through inserting into the nasal cavity through nostrils. 
  • Pariseka  (ocular  irrigation): Pouring of thin streams of medicated solution to the eye continuously for stipulated period from a height of 4 Angulas.
  • Rasayana Chikitsa (Reuvinative treatment): Chakshu Rasayna as mentioned in Kamya Rasayna

Hetupratyanika chikitsa (Lifestyle changes as a way of  treatment)
This plays a major role. Hence along with the treatment necessary lifestyle modifications has to be advised. Some of the required changes are:  

  • Avoid excessive air movement: windy conditions – outside or inside 
  • Avoid hot, dry environments and to add moisture to the air. 
  • Air Conditioning is as bad as heaters for increasing the evaporation of tears. 
  • Wear glasses on windy days and goggles while swimming.
  • The wraparound style of glasses may help reduce the effects of the wind.
  • Sunglasses and swimming goggles protect eyes from the Sun and  chemicals in pool water that can dry the eyes respectively.
  • Take frequent breaks: While watching TV, reading or working at a computer. 
  • Position the computer screen below eye level: Computer screen below eye level keeps the eye open narrowly. 
  • This may help slow the evaporation of tears between eye blinks. 
  • Stop smoking and avoid passive smoking

Yoga Advised
Yogic practices help to reduce eye strain and also build up the stamina of eye muscles. Mainly ShatKriyas like Trataka & NetiKriya help in improving the vision & maintain eye health