वृद्धः काचो दृशं कुर्याद्रजोधूमावृतामिव । स्पष्टारुणाभां विस्तीर्णां सूक्ष्मां वा हतदर्शनाम् ॥ ११ ॥
Kacha when grows older, makes the sight of objects as though covered with dust and smoke, of well-defined red color, wide spread (expanded) or small in size and loss of vision.
स लिङ्गनाशो वाते तु सङ्कोचयति दृक्सिराः । दृङ्मण्डलं विशत्यन्तर्गम्भीरा दृगसौ स्मृता ॥ १२ ॥
This stage is Linganasha. Increased Vata causes constriction of the veins of the organs of vision in-drawing of the Dristi Mandala (organ of vision). This condition is called Gambhira Dristi.
पित्तजे तिमिरे विद्युत्खद्योतद्योतदीपितम् । शिखितित्तिरिपत्राभं प्रायो नीलं च पश्यति ॥ १३ ॥
In Timira, born from Pitta, the person sees lightning (flashes of light), glow worms and burning lamps etc. (before his eyes), objects appear as deep blue in color like the feather of the peacock and Tittiri (partridge).
काचे दृग्काचनीलाभा तादृगेव च पश्यति । अर्केन्दुपरिवेषाग्निमरीचीन्द्रधनूंषि च ॥ १४ ॥
In Kacha, the organ of vision appears as Kachanila (light blue). So, the person sees objects in the same color; the sun, the moon, fire, mirage, a rainbow as surrounded by haloes (colored rings).
In Linganasha of Pitta origin, the dristi (organ of vision) is blue like that of a bee, incapable of seeing and is unctuous. It is known as Hrisva Dristi, and the person sees only very little.