Cats are omnivores, but they prefer meat. In terms of health, a proper diet with meat is very beneficial for a cat's well-being. Most people know that cats love fish, but they don't know why. There's a claim online that cats that don't eat meat for a long time can go blind. Is this true? 
I. Why do cats love to eat fish?
1. Cat lovers know that cats have bright, expressive eyes, which is largely due to their diet. Cats are nocturnal animals, and to adapt to complete darkness, they must possess excellent vision. Taurine is a substance that can improve night vision. This sulfur-containing non-protein amino acid accounts for 50% of the total free amino acids in the retina and promotes the function of photoreceptor cells in the cat's retina. It is known that a lack of taurine in a cat's diet can lead to retinal degeneration, and long-term deficiency can result in blindness.
2. Cats cannot synthesize taurine in their bodies. Because cats lack the rate-limiting enzyme for taurine synthesis—cysteine-sulfinate decarboxylase—they cannot synthesize taurine from methionine and cysteine and must extract it from animal protein. Studies show that many animals contain taurine, with fish and shellfish being the richest sources, and mice also containing significant amounts. This explains cats' "hobby" of eating fish and mice. Furthermore, commercially available cat food contains substantial amounts of taurine.
3. Why did fish in the water become food for cats on land? One explanation is that ancient Egyptian fishermen fished on the lower Nile River, and cats were kept on the boats to catch mice. When the cats didn't have enough food, the fishermen would feed them the miscellaneous fish they caught. The cats were very interested in this delicious and nutritious food, and gradually developed a habit of eating fish, which they passed down. However, this "theory of acquired inheritance" is highly questionable because the core spirit of animal evolution is "natural selection," and the acquisition of "superior genes" is not widely accepted in academia.
4. In fact, not all cats are highly adapted to terrestrial life. When people think of cats, they often think of "domestic cats," but domestic cats are only close relatives of wild tabby cats. Not many domestic cats can swim, but their close relatives, the leopard cat and the fishing cat, are both excellent swimmers in the cat family.
5. They are adept at climbing trees and can also swim. They mainly inhabit forests and rainforests, usually damp areas close to rivers. Because they can swim, in addition to small mammals such as rodents, birds, and reptiles, fish and amphibians are also on their menu.
6. Unlike other felines, the fishing cat has semi-webbed toes, making it an excellent swimmer and diver, allowing it to move freely in semi-aquatic environments. Similar to its close relative, the leopard cat, the fishing cat inhabits freshwater-rich areas below 1500 meters in altitude, including rivers, streams, reed wetlands, and mangrove wetlands. However, due to the extensive destruction of the wetlands and forests it depends on, coupled with the overexploitation of fisheries, this beautiful creature is now on the verge of extinction.
7. It's important to note that while cats love fish, "too much of a good thing" applies. Fish-based diets are high in histamine, a chemical messenger in animals that can affect many cellular responses, including allergies, inflammation, and gastric acid secretion. If a cat is allergic to fish, coupled with potential digestive upset, this foodie could gradually stop eating fish altogether, and even die. 
II. Cat Eye Care
1. Regularly check the cat's eyes.
Some cats have a tendency for tears to accumulate in their eyes, causing discoloration of the surrounding fur. If a cat experiences visual impairment, it may become restless and irritable.
2. The Importance of Caring for Your Cat's Eyes
Long-haired cats are prone to eye diseases. Their tear ducts can become blocked, causing their eyes to lose their luster, which requires cleaning.
Short-faced cats often suffer from tearing and eye discharge because their nasolacrimal ducts are shorter than those of other cats. Their naturally short nasal cavities cause their bright eyes to be constantly filled with tears. Over time, a large amount of reddish-brown substance is produced on their cheeks, leaving unsightly tear stains on their beautiful faces. Therefore, daily eye care is especially important for short-faced cats.
3. Cleaning measures
(1) General cleaning
Before cleaning, check for any signs of visual impairment. Use a small clean tissue or cotton swab dipped in baby oil to gently wipe away any dirt, including tears and eye discharge, from the cat's eyes and face, keeping the skin and fur as dry as possible. Use a different clean tissue or cotton swab to clean the other eye and cheek.
(2) Use of cat eye drops
Apply 2 to 3 drops to each eye; a little is unnecessary. Lift the upper and lower eyelids to ensure the medication fully contacts the mucous membrane inside the eye. Have the cat close its eyes and gently massage the skin on its face to keep any excess liquid in the affected area. If the amount of liquid seems insufficient or drips, apply a small amount more. Try to keep the cat's eyes closed to prevent contaminated liquid from flowing back into them. Then, carefully wipe the cat's eyes, eye sockets, and face clean with a clean tissue.
Cats do indeed eat more meat than dogs. Don't assume that cats can live without meat; that's incorrect. Of course, any food you feed a cat needs to be given in moderation; too much will only have the opposite effect.
