The 8th chapter of Charaka Samhita Sutrasthana is known as Indriyopakramaneeya Adhyaya. It explains in detail regarding – the Mind and sense organs, their qualities, functions and how to protect them etc.
Table of Contents
Panchendriya – 5 sense faculties
Panchendriy Dravya – 5 fundamental materials
Panchendriya Adhistana – 5 sense organs
Panchendriy Artha – 5 sense objects
Panchendriya Buddhi – 5 sense perceptions
These set of 5, form Pancha panchaka. The concept of gaining knowledge has been explained with the help of these factors.
Qualities of mind
Mind is Atindriya – cannot be perceived by sense organs.
Mind connects sense organs with the intellect. It is known as Satva or Chetas.
Mind’s action is determined by the quality of Atma (soul), like happiness, misery etc.
Mind acts as the driving force for all the sense faculties. 
Mind is one, not many
In an individual, the mind appears to have multiple characters due to its various actions like
Sva Artha – perception of its objects,
Indriya Artha – perception of the objects of the sense faculties,
Sankalpa Vyabhicharana – its disposition, determination, swift association with sense organs to receive knowledge,
Its association with Rajas, Tamas and Satva qualities.
Though mind does so many actions so swiftly, there is no multiplicity of mind. It is one and only one.
Hence the mind does not get associated with multiple sense organs at a single point of time. 
Quality determination of mind
The mind of a person is qualified on the basis of the type of his repeated action. As one indulges in particular types of good or bad deeds, his mind gets the qualities based on one’s actions over a period of time.
The role of mind in perception of knowledge
The sense faculties are capable of perceiving their respective objects only when they are connected to Buddhi (intellect) by mind. Mind acts as a connecting point between sense organs and intellect. 
Panchendriya – 5 sense faculties
Ghranendriya – Olfactory system
Rasanendriya – Gustatory perception system
Chakshurendriya – Ocular system
Sparshanendriya – Somato sensory system
Shravanendriya – Auditory system
Panchendriya Dravyani – 5 basic materials
Prithvi – earth
Ap – water
Teja – fire
Vayu – air
Akasha – ether
Panchendriya Adhishtana – 5 sense organs
Ghraana – Nose
Rasana – tongue
Chakshu – eyes
Twak – skin
Karna – ears
Panchendriya Artha – 5 sense objects
Gandha – smell
Rasa – taste
Roopa – shape
Sparsha- touch sensation
Shabda – sound
Panchendriya Buddhi – 5 sense perceptions
Ghranendriya buddhi – Intellect obtained by smell
Rasanendriya Buddhi – Intellect obtained by tasting
Chakshurendriya Buddhi – Intellect obtained by seeing
Sparshanendriya Buddhi – Intellect obtained by touching
Shravanendriya Buddhi – Intellect obtained by hearing
These 25 form Pancha Panchaka.
The knowledge is the product of combination of objects (Indriya Artha), sense faculties (Indriya), mind (Manas), intellect (Buddhi), and the soul (Atma) they are momentary and determinative. 
Shloka recitation video
Spiritual elements and their actions
The mind, the object of the mind, intellect and soul – these four factors constitute spiritual elements and qualities.
They serve as factors for promoting an individual to indulge or refrain from virtuous and sinful acts. Like every object (Dravya) has its own Karma (function), the functions of human beings are dependent on the above 4 factors. 
Correlation of Panchabhutika elements with five sense faculties:
The sense faculties (Indriya) are to be inferred. They cannot be perceived directly. They consist of all the five Mahabhutas (5 basic elements).
The olfactory, gustatory, visual, tactile and auditory faculties are specially dominated by Prithvi (earth), Ap (water), Tejas (fire) Vayu (Air) and Akasha (Ether) respectively.
The sense faculties perceive only such of the objects as are dominated faculties. This is so, because, the very nature of sense faculties is determined by the particular Mahabhuta it is specially made of.
Sense faculties are capable of perceiving only the objects having the same qualities. 
For example, olfactory system can only perceive smell, tactile system can only perceive touch sensation and so on.
How do sense organs get vitiated? How do sense organs gain knowledge?
Sense organ vitiation, gaining of knowledge
The sense faculties, together with the mind get vitiated by
Atiyoga – excessive utilization (example: seeing one object for a long period of time)
Ayoga – non- utilization (Eg: sitting in darkness, not seeing anything for a long period of time) and
Mithya Yoga – wrong utilisation of the objects concerned. Eg: seeing very bright object, gazing at Sun etc.
This leads to vitiation of respective sense organs. When the sense organs are utilised properly, they help in acquiring respective knowledge. 
Object (Artha) of Manas (Mind) is Chintana (thinking).
The proper / excessive / wrong utilization of mind is responsible for normal or abnormal mental conditions. 
Principles of preventing Psychological disturbances
In a healthy state (Prakruti), mind and sense faculties are not disturbed and they perform their duties in a healthy way. In order to maintain mental health, one should make all positive efforts. This can be achieved by the performance of duties after duly considering their pros and cons, with the help of the intellect (Buddhi), together with the sense faculties (Indriya) applied to their respective objects (Indriya Artha) Hence, person, who is desirous of his own well being should always perform Nobel acts (Sadvritta) with proper care. 
Sadvritta – noble deeds
One who acts after due analysis of pros and cons simultaneously fulfills both the objectives of maintenance of positive health and control of sense faculties. Such Sadvritta (noble deeds) are explained further.
One should pay respects to the
Deva – Gods,
Go – Cows,
Guru – Teacher
Vruddha – elderly,
Siddha Acharyas- higher spiritual experts and spiritual teachers.
One should give due respects to fire.
One should wear / consume good herbs.
One should perform Sandhya Vandana ( a vedic ritual aimed at cleansing mind and body) during dawn and dusk, twice a day
One should clean excretory orifices and feet frequently
One should have a hair cut, shave and nail cut- thrice every fortnight
One should wear good apparel be happy, apply scent, wear good dress, comb the hair, always apply oil to the head, ears, nostrils and feet,
Dhumapana – do herbal smoking,
Purva Abhibhashi – One should not wait for the other to wish him. One should try to wish first.
Sumukha – One should have a delightful face,
Protect people in affliction, offer oblation, perform religious ceremonies, donate, pay respect to cross roads, offer bali (a religious oblation), honor the guests, offer pinda (rice and sesame seed lump, offered in memory of the departed souls of the family (Shraaddha)
One should envy in the action, competition and cause but should not envy in the results.
Nishchinta – do not worry much,
Nirbheeka – be fearless,
Be bashful and wise, have enormous enthusiasm, be clever, forbearing, virtuous, having faith in God.
Be devoted to higher spiritual teachers and those who are advanced in modesty, intellect, learning, heredity and age
Use an umbrella, a stick, a turban, shoes and see only six feet forward while walking
Behave auspiciously and display good manners
Avoid places with dirty apparel, bones, thorns, impure hair, chaff, garbage, ash, fragments of earthen vessels, and the places of bath and worship,
Stop exercise before getting tired excessively,
Be friendly to all creatures, reconcile the angry, console the frightened, be merciful to the poor, be truthful
Have compromising nature, be tolerant towards unpleasant words uttered by others, be controller of intolerance,
Be peaceful and conquer the very roots of attachment and hatred. 
Do not lie down on others property. Do not take over others properties.
Do not long others wives or property. Do not indulge in hatred or sinful activities. Never be vice.
Do not disclose other’s secrets Ditch un-virtuous, traitors, lunatics, fallen persons, abortionists, mean and crooked people.
Do not ride dangerous vehicles. Do not sit on a hard seat of knee height.
Do not sleep on a cover-less, pillow-less bed. Do not sleep or walk on uneven slopes of mountain.
Do not climb an uneven tree. Do not take bath in a river having turbulent flow.
Do not sit in the shadow of people of noble families.Do not move around place of fire, laugh loudly, release flatus with sound.
Do not yawn / sneeze / laugh without covering mouth. Do not itch the nostrils, grind the teeth, sound the nails, knuckles, strike the bones, scrape the earth, cut the straw with hand, rub the pile of mud, maintain improper position of different parts of the body
Do not see the planets or undesirable, impure or condemned object. Do not produce “hum” sound before a corpse
Do not cross the shadow of a sacred tree, a flag, teacher, a respectable person or an undesirable person
During nights, do not enter the premises of a temple, a scared tree, public courtyard, crossroad, garden, cemetery and slaughter house
Do not enter a solitary house or forest alone Do not have relations with women, friends or servants of bad conduct
Do not be an enemy of good men. Do not be a friend of bad men.
Do not keep doing crooked things as a choice of action. Do not indulge in ignoble or frightening acts.
Do not take undue unnecessary courage. Do not sleep,vigil, bath, drink or food in excess quantity
Do not sit for a long time with knees up. Do not approach snakes or animals with dangerous teeth and horns
Avoid easterly wind, sun, snow fall and storms. Do not provoke a quarrel
Do not come close to the fire without concentration of mind or without a wash after taking food
Do not heat the body by keeping fire below
Do not take bath unless free from exertion. Do mouth gargling before bath. Do not take bath being naked.
Do not touch your head with the apparel worn at the time of bath or strike the tip of the hair.
After taking bath do not wear the same cloth.
Do not go out without touching gems, ghee, feet of respectable persons, auspicious objects and flowers
Do not pass through by the right side of respectable persons or auspicious objects. 
Healthy Diet Practices
Do not take food without wearing precious stones in hand or without taking bath.
Do not take food wearing torn apparel or without reciting mantras or without offering oblations to the Gods or without making offerings to the departed ancestors, teachers, guest and dependents or without applying sacred scents or without garlands or without washing hands, feet and face or without cleaning the mouth.
Do not take food with face turned towards the north or with disturbed mind or surrounded by the insincere, uncultured, dirty or hungry persons.
Do not take unknown dishes. Do not take food at improper place and time or in a place surrounded by many persons or without first offering the fire or without sprinkling with scared water or without sanctifying it with sacred mantras.
Do not take the food that you hate.Do not take food which is dirty or which has been served by the opponents.
Except in the case of meat, rhizomes, dry vegetables, fruits and sweets, do not take stale food.
Do not consume the entire food except in the case of curd, honey, salt and roasted grain flour and ghee.
Do not take curd at night.
Do not take roasted- grain-flour without mixing it with ghee and sugar or in the night or after meals or in large quantity or twice daily or interrupted with water intake, Do not eat by tearing with teeth. 
Do not sneeze or eat or sleep in prone position (lying upside down, tummy facing downwards, sleeping on tummy).
Do not attend to any other work while under the pressure of natural urge
Do not let out sputum, excreta or urine in front off the wind, fire, water, the moon, the sun, the Brahmans and the teachers.
Do not take water on the roadside or in a public place. Do not drink water at the time when you are supposed to have food. Do not let out nasal excreta during the course of recitation, religious rites, studies, religious offerings and auspicious acts. 
Do not insult women. Do not have too much reliance on them, do not confide secrets to them. Do not authorize them indiscriminately.
Do not indulge in sex with a woman during her menses or with a woman who is suffering from a disease or is impure or is having infection, or a woman with an ugly appearance, or with bad conducts or manners, or with the one devoid of skill.
Do not indulge in sexual intercourse with a woman who is not friendly or does not have passionate desire or is passionately attached to somebody else or is married to somebody else or a woman of another caste.
Do not indulge in sex in any organ other than the genital organ. Avoid sex under religious trees, in a public courtyard, on a cross- road, in a garden, at cemetery, at slaughter house, in water, in clinics or in the house of Brahmans or teachers or in temples. Avoid sex during dawn ,dusk and on inauspicious days. Avoid sex being impure, without aphrodisiacs, without intense desire or without erection or without having taken food or with excessive intake of food or in an uneven place or while under the pressure of the urge for urination, after exertion, after physical exercise, in fasts, having exhaustion or in a place having no privacy. 
Do not speak ill of noble persons and teachers. Do not perform spells, worship of sacred trees and superiors, and studies while being impure. 
How to study properly
Do not study during nonseasonal lightning, when there is excessive brightness, when there is outbreak of fire, during earthquake, during important festivals, during fall of meteors, during solar or lunar eclipse during new moon day or during dawn or dusk.
Do not study without being initiated by a teacher.
While studying, do not recite words incompletely in low sounds nor in high / coarse voice, with improper accent, without sitting symmetrically. Do not recite very fast or very slow. Do not delay in between recitation. Do not recite in high or low pitch. 
Do not deviate from generally approved principles. Do not break code of conduct and ethics. Do not walk during night nor in an inappropriate place. Do not indulge in eating, studies, sex or sleep during dawn or dusk.
Do not make friends with children, the old, greedy, the fools, persons under affliction or eunuchs.
Do not be attracted towards wine, gambling and prostitutes. Do not expose secret parts of the body. Do not insult anyone. Do not be conceited, unfriendly. Do not back bite.
Do not insult Brahmans, do not beat cows. Do not use harsh words towards elders, teachers, persons grouped together or kings. Do not speak too much. Do not disregard kin, folk, persons attached or persons who had helped you during the time of misery and those who know secrets. 
Do not be impatient or over-bold. Do not neglect servants. Do not doubt your kin. Do not enjoy alone. Do not have uncomfortable character, conduct, manners and diseases. Do not rely / suspect everyone. Do not be over-meticulous. 
Do not have the habit of procrastination and postponing things. Do not do anything without proper examination. Do not be a slave to senses. Do not be fickle minded. Do not inflict too much burden over the intellect or senses. Do not act on anger / rejoicing. Do not grieve continuously. Do not be over-happy about achievements or overly depressed about the loss.
Always remember your nature and act accordingly. Have faith in correlation of cause and effect. Have faith that good deeds bring good results. Do not be complacent. Do not lose spirit. Do not contemplate on your insults. 
Practices regarding fire worship
Do not offer oblations to the fire with cow ghee, intact grains, sesame seeds, Kusha grass and mustard seeds while in impure condition. One should touch water, reciting- Apo hi stha( Rgveda X.9.1) with the following invocation:-
“Let not fire go away from my body”,
“May the Wind- God bring life”,
“May Lord Vishnu give me strength (Bala)”,
“May Lord Indra give me Energy (Veerya)”,
“May the benevolent waters enter my body”.
After cleaning his lips and feet twice, one should touch with water all the orifices of the head and the head. 
Social good deeds
One should keenly follow the path of Bramacharya, knowledge, charity, friendship, compassion, happiness, detachment and peace.
In this chapter on” the Description of Sense Organs”, five pentads, mind, four causative factors and good conduct are explained in detail. One who keenly follows these prescriptions for maintenance of positive health will be devoid of all diseases and lives for hundred years, without meeting an untimely death. He will be praised by the good. He will earn fame allover the world. He will attain virtue , wealth and will become a friend of all living beings. The one with virtuous acts attains the divine abode of good souls, after death. So this code of conduct should always be followed. [30-33]
Even if something is not stated here but that is prescribed elsewhere as a virtuous act, that should also be followed. 
Thus ends the eighth chapter of Sutrasthana of Charaka Samhita, called Indriyopakramaneeya Adhyaya.