Which of the following symptoms indicates a possible problem with a dog's eyes?

Outward rolling eyelids, known as ectropion, can indeed indicate a problem with a dog's eyes. This condition occurs when the eyelids roll outward, exposing the inner lining of the eyelid, which can lead to irritation, dryness, and potential health issues such as conjunctivitis or corneal damage. Proper eyelid function is crucial for protecting the eye and maintaining moisture, so any abnormality like outward rolling is a sign that the dog may need veterinary evaluation to address any underlying issues.

Nasal discharge, excessive scratching, and heavy panting, while they may signal different health concerns, are not specifically indicative of an eye issue. Nasal discharge can point to respiratory problems; excessive scratching often relates to skin irritations or allergies; and heavy panting could signify heat stress, anxiety, or pain. Each symptom serves its own purpose in diagnosing distinct conditions in a dog, but none are directly associated with eye health in the way that outward rolling eyelids are.