Best Answer: The pupil size limits the the amount of light that enters the eye. There are also day-time photoreceptors, the cones, which occur with three kinds of photo-sensitive pigments, for red, yellow-green, and blue.
Those âdevotedâ dogs lying on their mastersâ graves? Theyâre depressed. âMany dogs are simply depressed for their whole lives because theyâre deprived of the normal amount of attention, exercise, and stimulation they need from day one. These humans wonât know they have a problem and wonât want the dog any livelier as that wouldnât fit in with their lifestyle,â says Tamara.
But what are the symptoms you need to look for at home? Depression: Not all dogs will act depressed when they are sick. In the wild, animals that act sick are more likely to die. You need to watch your dog at all times and be aware of what is normal for him. If your dog is depressed, do something about it. Loss of appetite: Some dogs will miss a meal at times, and you should be aware if you have the type of dog that misses meals.