A cat's health can be assessed by observing its eye discharge. Based on the color and shape of the discharge, the following conclusions can be drawn:
1. White or translucent eye discharge is normal fresh eye discharge.
2. Black eye discharge is dry eye discharge, which usually appears after the cat wakes up from sleep. You need to pay attention to the condition of the cat's eyes. 
3. Light eye discharge may indicate that the cat is eating too much oil or salt, or is lacking in vitamins and fiber, and its diet needs to be adjusted.
4. Black or dark brown eye discharge may indicate bleeding in the cat's eyes, requiring immediate veterinary attention.
5. Yellow-green eye discharge indicates that the cat may have conjunctivitis or keratitis, and needs to be treated with pet-specific eye drops.
6. Dark red, gelatinous eye discharge or eye discharge with blood streaks indicates that the cat's eye has been injured and requires immediate veterinary attention.
In short, pay close attention to your cat's eye discharge. If any abnormalities are found, you should adjust its diet or seek veterinary treatment promptly.
