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Blinding Betta Fish? Diamond Eye And Moon Eye Explained

What Is Diamond Eye?

Also known as moon eye, diamond eye is a genetic trait that results in overgrowth of scales over the eyes of a fish, leading to blindness. An important distinction is that the scales grow over the eyes and do not anatomically impact the retina.

  • Diamond eye can impact one or both eyes and can partially or fully cover the eyes

  • The condition usually happens slowly over time, taking months to years


Are All Betta Fish At Risk Of Diamond Eye?

Diamond eye can actually impact many different types of fish, not just bettas. But no, not all betta breeds are at risk. The breeds at highest risk of this condition are platinum dragonscale, metallic and marble bettas.


How Does Diamond Eye Affect A Betta Fish?

The main impact of diamond eye is blindness. Luckily, diamond eye usually does not negatively impact lifespan, but it can impact quality of life. A healthy and happy life for your betta is still very much so possible! Diamond eye also does not physically hurt the fish.


Why Does Diamond Eye Happen?

This condition is resultant from selective breeding of these specific types of betta fish (platinum, metallic and marble). The overgrowth of scales is an unwanted trait that so happens to spread through genetic lines.


Are There Treatments To Diamond Eye?

Unfortunately, there are no known recommended treatments. Experienced bleeders have reportedly been able to successfully surgically remove the layer of scales over the eyes, however I cannot recommend anyone to do this, as failure rates are high.


How Can I Prevent Diamond Eye From Happening To My Betta Fish?

There are no known effective prevention methods, since it is a genetic condition. People have recommended almond or banana leaves to allow the tannins to thin out the scales, however I also cannot recommend this as the leaves will thin out other scales too. There is also contradicting data out there on this intervention.


What Should I Do If My Fish Is Developing Diamond Eye?

There are a number of things that you can do before your betta fish's diamond eye reaches its final form. Most recommendations below are regarding conditioning your fish to know when to eat/find food using other senses instead of sight.

  • Establish a feed spot by consistently feeding your betta fish in the same spot of the tank every day

  • Shine a flashlight at your betta fish, briefly before feeding, to associate light with food

  • Lightly tap the glass before feeding to associate that sound and vibration with food

  • Some people exclusively feed in feeding rings because of the high contrast of the ring and the consist location

  • Feed bright food like blood worms or Tetra Betta Floating Mini Pellets, foods like bug bites might be more difficult to find

Other tips:

  • Refrain from re-scaping your aquarium, so you do not disrupt familiarity for the fish

  • Make sure everything in the tank is soft and/or smooth (i.e. real plants, silk fake plants and non-jagged hardscape)

  • Low current is even moreso important to keep stress levels low

In Conclusion…

Do not fret if your fish is developing diamond eye. Just remember that it is completely possible for them to live normal happy lives if you condition them early with the above feeding methods.

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Hi! If you're looking for a place of informational integrity, you're at the right place! My name is Harry, I'm a Pharmacist with a love for fish keeping and the aquarium hobby. I'm not the most experienced fishtuber/fish keeper out there, but if there is one thing pharmacy school taught me, it's how to learn, diligently and efficiently. My mission is to address the misinformation and lack of accessibility of accurate information in the fish keeping hobby through tips, tricks, reviews and research-based best practices.

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-Harry, PharmD

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