What is the primary function of the cornea in dogs?

The primary function of the cornea in dogs is light refraction and transparency. The cornea is the clear, dome-shaped front surface of the eye, which plays a crucial role in focusing light onto the retina. Its unique curvature refracts incoming light, helping to direct it accurately towards the back of the eye for optimal vision. Additionally, the cornea is transparent, which is essential for allowing light to pass through without obstruction; any cloudiness or opacity can significantly impair vision.

In relation to the other options, while the cornea does play a supportive role in protecting the inner structures of the eye and is involved in the immune response, its main function is providing clarity and focusing light. The regulation of pupil size is primarily managed by the iris, not the cornea, and color perception is a function of the retina's photoreceptor cells, not the cornea itself. Thus, light refraction and transparency are the key elements that define the cornea's essential role in canine vision.