Are Shubunkins With Black Eyes Blind?

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Shubunkins with black eyes can be striking fish, can’t they? Most of us have seen them before. After all, they’re such a common sight at the fish store. In almost every batch of shubunkins for sale I’ve seen at least one or two with black eyes.

But, I’ve heard the question a hundred times—are shubunkins with black eyes blind?

Shubunkin with small amount of black on part of its eye.
This shubunkin has a small amount of black on part of its eye. Read my article on stocking levels to better understand how many goldfish you can keep in your aquarium.

So, in this article I want to address any concerns you might have about black eyed shubunkins. Maybe you already own one or you’re thinking of purchasing in the future.

Why Do Some Shubunkins Have Black Eyes?

Before we can get to the crux of the topic, it’s a good idea to lay down some basics. What are shubunkins and what causes their coloration?

This shubunkin has a completely black eye. Is it blind? This question has been answered briefly on the UK Practical Fishkeeping website, but I’d like to into more detail in this article.

Shubunkins are a variety of goldfish. Their unusual coloration comes from the combination of their nacreous scales and calico pattern.

Nacreous scales are an intermediate between naturally metallic goldfish scales and transparent scales. This scale type occurs when a fish carries the gene for both metallic and matte scales.

The calico coloration is a combination of a blue base, with red/orange patches, and black patches. The colors can spread across any part of the fish’s body, including the fins, and of concern to us, the eyes. This is why many shubunkins have completely black eyes.

Are Shubunkins With Black Eyes Blind?

Shubunkins with black eyes are not inherently blind.

To understand why we need to consider how eyes work. Fish eyes aren’t too different to our own eyes. And where fish eyes do differ from human eyes isn’t really relevant to this explanation.

This is a diagram of a human eye. While fish eyes are different from our own, in the important ways they are quite similar.

This is a diagram of a human eye. While fish eyes are different from our own, in the important ways they are quite similar.

Just like our eyes, shubunkin eyes have a pupil and a retina.

The pupil of any fish’s eye appears solid black for the same reason ours do, i.e. it’s a hole that leads into the dark interior of the eyeball. When a shubunkin’s iris is also black, it gives the impression that the entire eye is black, but that is not the case. The iris may well be colored black, but the pupil persists—i.e. it is just a hole that appears black at the center of a black iris. The fact that a shubunkin’s iris might be colored black by its pigmentation doesn’t compromise the pupil’s ability to allow light into the eye.

Shubunkin with partial black coloration over its eye.

Nor does a black iris stop the light that enters the eye being captured by the retina. That light (i.e. the information required to produce an image for the fish to see) is then transmitted to the brain via the optic nerve without hindrance.

Of course, any goldfish (shubunkins included) might be blind for other reasons, but it would not be caused by any black coloration of the iris. To put your mind at ease, blindness in goldfish is not common in my experience.

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