How To Measure Eye Relief For A Scope & How Is It Adjusted

Article Write: | Latest Update On: July 15, 2021

Ever faced an issue like losing sight of your target while you are hunting? Well, it can happen due to a number of reasons and the most common reason behind this is incorrect eye relief. Incorrect eye relief makes the lens blurry. Hence it causes a sudden disruption while focusing.

What is eye relief? Eye relief is the distance between shooters’ eyes and the last lens of associated rifle scopes. Therefore, it is clear that incorrect eye relief can lead to several hazardous incidents. Along with losing scope’s functionality, faulty eye relief can lead potential injury to the shooter. Therefore, knowing How To Measure Eye Relief For A Scope can be worthy. Basically, 10mm to 15mm distance will provide the best comfort.  Learn more  about it from the discussion below.

About Eye Relief For Scope

Eye relief is the gap between the last surface of your rifle scope lens to your eye. It is one of the essential things that helps the shooters to get a complete sight view without any distortion or obstruction. Without adequate eye relief, shooters wouldn’t be able to gain an accurate and unobstructed view.

Eye Relief For Scope

Basically, eye relief is measured in millimeters or inches and from 13 mm to around 4.5 inches of eye relief is the standard eye relief option. However, most of the eye relief measurements ranges from 1 to 4 inches or 4 to 100 millimeters. So, whether you’re using a simple scope or a cheap high power scope, you must consider the accurate eye relief distance to get an accurate and entire field view.

Why is eye relief important?

Earlier we have discussed what eye relief is, now you can probably think if eye relief is important or not. Well, of course, it is one of the essential things you have to look at. If you don’t want to come back from hunting with a bandage over your eyebrow then you must give your attention to it.

eye relief important

The scope will perform at its best when everything in its mechanism is in a proper adjustment. For instance, if you don’t properly measure eye relief for a scope, it will reduce the scope effectiveness. Along with reducing scope’s effectiveness, wrong eye relief can cause potential injuries too.

Clipped image, fuzzy or blurry field view is another issue that comes from improper eye relief. Wrong eye relief will also negatively affect your viewing area as well as image quality. So to get a proper sight view, you must ensure adequate and proper eye relief.

How To Measure Eye Relief For A Scope

To get a clear sight view and a safe and comfortable position for shooting, you must measure the eye relief. It shows how close you have to bring your eye to the scope to see the full picture. However, Eye relief works through two factors, and they are –

How To Measure Eye Relief For A Scope

  1. Magnification
  2. Field of View

However knowing how manufacturers calculate the eye relief will get you a better idea about measuring it.

The scope is measured in mm and based on it’s or exit pupil’s size manufactures calculate the eye relief. Manufacturers consider both the scope size and magnification option to determine the distance of eye relief.

However, there are many types of eye relief and standard one is 3.5 and 4.5 inches. If you calculate them into mm, then it would be around 50 to 110mm. When it’s about measuring eye relief for your scope, just follow the specifications provided by the scope manufacturer.

By following the provided specifications, you can easily get the best possible view with the best light transmission.

How to Adjust Eye Relief

You will get optimal eye relief from your rifle scope manufacturer. However, sometimes you may not find that position comfortable, so adjusting it by yourself can be a good idea. Many shooters may think they need to go through some complex math, actually it is not. Here we will show you how to adjust eye relief on a scope as your preference.

How to Adjust Eye Relief

Step 1: Attach the scope to your rifle with a little loose, so you can make adjustments while finding the suitable eye relief.

Step 2: Now mount the rifle on a stable surface with adequate lighting. Then place the rifle on your shoulder to assume the most ideal and comfortable position.

Step 3: On the third step, you need to find your comfort level scope position and try to focus on how it feels.

Step 4:  Now adjust the scope to get the entire field of view. You may need to repeat this process several times to find a comfortable position.

Step 5: Once you find the most clear view and comfortable position, now simply tighten the scope ring.


Though many hunters spend most of their time on several components of their rifle, plenty of them skip eye relief. It happens because either most of the hunters don’t know about it or they find it tedious. But, eye relief is a simple thing hunters need to pay attention, which will help to accurately hit the target.

Since you know How To Measure Eye Relief For A Scope, now you can enhance your target hitting ability. However, remember that different rifle or scope types may require different levels of distance. So, if you find it difficult to adjust your eye relief for your type of scope, you better follow the manufacturer’s recommendations.

Hi, I am Jhon Adam, I am an ex-military and now I run a business where I sell security tools, arm protection gadgets, gun vaults, scopes for the rifles, and other related accessories. Because of this business, I have to deal with so many clients who felt insecure about their security tools. Like it is quite risky and dangerous to let the personal protective gun in an insecure way. Because they don’t have gun safe vaults. Some people facing difficulties with their hunting rifles scope or etc. Every day they come to my shop they come with a new problem.

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