Information
Helpful Information
We understand how confusing the world of veterinary ophthalmology may seem, so we hope that the following information will be of assistance.
Visual Field and Depth Perception
- Dogs and Cats (Predators): Have forward-facing eyes that provide a high degree of binocular overlap, which is essential for depth perception and accurately pouncing on targets.
- Dogs have a total visual field of roughly 240 degrees.
- Cats have a visual field of approximately 200 degrees.
- Rabbits (Prey): Have eyes positioned on the sides of their head, providing a nearly 360-degree panoramic field of view. This allows them to detect predators from almost any direction, though it results in a small blind spot directly in front of their nose.
Light and Night Vision
- Cats: The “champions” of low-light vision, requiring roughly six times less light than humans to see. They have vertical-slit pupils and a highly efficient tapetum lucidum (a reflective layer) to maximize light absorption.
- Dogs: Also possess a tapetum lucidum and superior night vision compared to humans, though they do not see as clearly in the dark as cats.
- Rabbits: Most active at dawn and dusk, they have many “rod” cells for dim light but lack a tapetum lucidum. This makes their vision poor in complete darkness compared to cats and dogs.
Colour Perception and Clarity
- All Three Species: Are dichromatic, meaning they see the world primarily in shades of blue and yellow. They generally struggle to distinguish between red and green. Dogs, cats (and rabbits to a limited degree) can however see UV light (which we cannot), allowing them to see things in the world that we are unaware of.
- Visual Acuity: Humans generally have much sharper vision.
- Dogs: Roughly 20/75 vision (they must be at 20 feet to see what a human sees at 75 feet).
- Cats: Generally between 20/100 and 20/200, making them quite nearsighted.
- Rabbits: Typically have a visual acuity estimated between 20/240 and 20/360.
