Common Issues with Red Dot Sights and Troubleshooting Them

Chris G.

Recently, a fellow shooter in our local shooting range experienced an unusual blurring effect in his red dot optic during a particularly rigorous and challenging obstacle shooting tournament. Initially, he attributed this issue to simple eye strain. However, as the problem persisted for a few weeks, it was clear that the issue was not with his sight, but with the red dot itself.

Both seasoned and novice shooters often face problems with their red dot optics such as blooming and flaring, irregular shapes, or trouble with adjustments. This article will tackle these common problems and offer insightful tips on how to resolve them.

A Short Description of the Red Dot

A red dot sight is a non-magnifying reflector that projects a red dot onto a spherical mirror or a specially coated lens. The red dot helps the shooter to quickly and accurately aim, acquire, and hit their target. The ease of use and reliability of a red dot make it a favorite among beginners and experienced shooters alike.

The sight’s operation is based on a light-emitting diode (LED) which emits a red dot onto a specially coated lens that reflects only the red wavelength. The shooter aligns this dot with the target and pulls the trigger. At the right conditions, range, and calibration, the bullet should hit the target that is “painted” by the red dot. 

A red dot sight does not magnify objects. It is designed to improve accuracy and speed on point-blank and short-range, usually up to 50 to 100 meters. Without any magnification, the field of view is extremely broad, simplifying the tracking of moving targets.

Common Red Dot Issues and Troubleshooting Tips

Red dot sights are generally reliable. But like any piece of equipment, they can encounter issues from time to time. Here are some common red dot sight issues and tips on how to troubleshoot them:

1. No Dot or Flickering Dot

  • Possible Causes
    • Dead or low battery power
    • Loose battery connection
    • Electrical issues
  • Troubleshooting Tips
    • Replace the battery with a fresh one.
    • Check the battery compartment for loose connections.
    • Inspect the electrical components for any visible damage.

2. Shifted Point of Impact

  • Possible Causes
    • Loose mounting screws
    • Recoil-induced movement
    • Impact or dropping the firearm
  • Troubleshooting Tips
    • Tighten mounting screws to the manufacturer’s specifications.
    • Consider using a thread locker on mounting screws.
    • Inspect the sight for physical damage and alignment issues.

3. Blurry or Distorted Reticle

  • Possible Causes
    • Dirty or scratched lens
    • Misaligned reticle
    • Optical coating damage
  • Troubleshooting Tips
    • Clean the lens with a microfiber cloth.
    • Check for scratches on the lens.
    • Realign the reticle according to the manufacturer’s instructions.

4. Parallax Error

  • Possible Causes
    • Incorrect eye position
    • Misalignment of internal components, particularly the lens, the aperture, or the LED emitter
  • Troubleshooting Tips
    • Ensure a consistent cheek weld and eye position.
    • If the parallax is adjustable, follow the manufacturer’s instructions for correction.

5. Sight Won’t Hold Zero

  • Possible Causes
    • Loose adjustment turrets
    • Recoil-induced movement
    • Poor-quality mount
  • Troubleshooting Tips
    • Securely tighten adjustment turret screws.
    • Consider using a high-quality mount for stability.
    • Check for damage to internal components affecting zero retention.

6. Flickering or Intermittent Illumination

  • Possible Causes
    • Loose or faulty wiring
    • Battery connection issues
  • Troubleshooting Tips
    • Inspect the wiring for loose connections or damage.
    • Ensure the battery is properly inserted and the compartment is clean.

7. Lens Fogging

  • Possible Causes
    • Sudden temperature changes
    • Humidity or moisture seeping into the red dot
  • Troubleshooting Tips
    • Allow the sight to acclimate to temperature changes gradually.
    • Use anti-fog solutions or lens wipes.

8. Excessive Glare in Bright Sunlight

  • Possible Causes:
    • Brightness setting too high
    • Sunlight angle
  • Troubleshooting Tips
    • Adjust the brightness setting to a level that reduces glare.
    • Change your shooting position or use lens shades if available.

9. Inconsistent Dot Size or Shape

  • Possible Causes
    • Reticle type or style
    • Internal component issues
  • Troubleshooting Tips
    • Refer to the manufacturer’s specifications for the intended reticle appearance.
    • Contact the manufacturer if the issue persists.

10. Environmental Damage

  • Possible Causes
    • Exposure to water, dust, or debris
    • Impact or rough handling
  • Troubleshooting Tips
    • Keep the sight protected with lens covers when not in use.
    • Inspect for any signs of damage or wear regularly.

Always refer to the red dot’s manufacturer’s manual for specific instructions in handling your model’s issues.

What About Shooters with Astigmatism?

Astigmatism is a common vision condition where the cornea or lens of the eye has an irregular shape, affecting how light is focused on the retina. The degree of natural astigmatism can vary from one person to another.

Shooters with astigmatism may experience challenges when using red dot sights. Astigmatism can cause the dot or reticle to appear blurry, distorted, or star-shaped. 

Challenges for Shooters with Astigmatism

  • Blurred or Distorted Dot: The red dot may appear stretched, smeared, or have a comet or starburst shape, making it appear misshapen instead of a crisp and clear dot.
  • Increased Glare and Halo: Astigmatism can enhance the perception of glare around the dot, making it more challenging to focus on the intended target.

Tips for Shooters with Astigmatism

1. Adjust Brightness Settings: Experiment with different brightness settings on your red dot sight. A lower brightness level might reduce the perceived distortion caused by astigmatism.

2. Try Different Reticle Types: Some shooters with astigmatism find that certain reticle types such as small dots or etched reticles may appear clearer than standard red dots.

3. Corrective Lenses: If you wear corrective lenses, ensure that your prescription is up-to-date. Wearing corrective lenses designed to address astigmatism may improve the clarity of the red dot.

4. Use Prism-based Optics: Prism-based optics, like prism scopes, can sometimes provide a clearer sight picture for individuals with astigmatism compared to traditional red dot sights.

5. Consider Holographic Sights: Some shooters with astigmatism find holographic sights to be more forgiving and less prone to distortion compared to standard red dot sights. Holographic sights project a holographic reticle that may appear clearer to individuals with astigmatism.

6. Consult an Optometrist: Schedule an eye examination with an optometrist to discuss your astigmatism and explore potential solutions. They may recommend specific corrective measures tailored to your vision. 

How To Maintain Red Dot Sights

a person cleaning the lens of the red dot sight

Proper maintenance is important for the consistent performance and longevity of red dot sights. Check out these maintenance tips to keep your red dot sight in optimal condition:

1. Regular Cleaning: Use a microfiber cloth to gently clean the lenses of your red dot sight. Remove any dirt, smudges, or debris that may affect visibility. Avoid using abrasive materials that could scratch the lens.

2. Protective Lens Covers: When not in use, keep lens covers on the red dot sight to protect the lenses from scratches, dust, and environmental elements. This helps maintain optical clarity.

3. Battery Checks: Regularly check the battery status of your red dot sight, and replace the battery according to the manufacturer’s recommended intervals. 

4. Secure Mounting: Ensure that the red dot sight is securely mounted on the firearm. Regularly check mounting screws for tightness to prevent movement caused by recoil, which can affect zero.

5. Storage in a Dry Environment: Store firearms equipped with red dot sights in a dry place. Avoid exposing the sight to extreme temperatures, humidity, or rapid temperature changes as these conditions can impact performance.

6. Check for Loose Components: Periodically inspect all components of the red dot sight, including adjustment turrets, battery compartments, and mounting hardware. Tighten any loose screws or components as needed.

7. Zero Verification: Regularly verify the zero of your red dot sight, especially after any modifications, disassembly, or transport. Ensure that the point of impact aligns with the reticle for accurate shooting.

8. Avoid Using Harsh Cleaning Chemicals: When cleaning the red dot sight, avoid using harsh chemicals or solvents that could damage the lens coatings or housing materials. Stick to mild lens cleaning solutions recommended by the manufacturer.

9. Protect from Impact: Handle the firearm with the red dot sight carefully to avoid impacts or drops. Sudden shocks can affect the internal components and alignment of the sight.

10. Adjustment Turret Security: Ensure that adjustment turrets for windage and elevation are securely fastened. Follow the manufacturer’s guidelines for adjustments, and avoid over-tightening. Periodically check for any unusual resistance or play in the turret movements.

11. Consult Manufacturer Guidelines: Regularly refer to the manufacturer’s user manual for specific maintenance instructions and guidelines. Different red dot sights may have unique requirements and recommendations. Following these guidelines will help you maintain the optic according to the manufacturer’s specifications.

12. Professional Inspection: If you encounter persistent issues or notice significant changes in performance, consider seeking professional inspection and maintenance from the manufacturer or an authorized service center. Professionals can diagnose and address issues beyond routine maintenance, ensuring the sight is in optimal condition.


Knowing how to troubleshoot common issues with your red-dot sight is important so you can maintain its optimal performance. 

Learning to fix these issues will prepare you to handle any unexpected situations. Regular upkeep and practice, coupled with a readiness to try different solutions, will improve your mastery of this optic.

About the author

The name's Chris. Just a regular dude who loves firearms. I've been shooting since I was a kid. My old man taught me the ropes.

I'll never forget the first time I missed an easy shot on a buck, thanks to a bum scope. The image was fuzzier than my dog's butt. After that, I got obsessed with understanding scopes. What makes the good ones tick and the bad ones trash. After a few years and a few thousand bucks, I learned what separates the winners from the losers. Once I had a good stockpile of knowledge, I launched this site.

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