Best Monocular in 2020: Budget, Compact, Hunting & Phone Compatible Monoculars!
Last Updated: May 19, 2020
A monocular is a highly undervalued optic. How can it stand to compete against binoculars and spotting scopes when clearly bigger always seems to be better?
Well, bigger isn't always better. The inherent advantage of a monocular is its lightweight and compact size.
While the best monoculars may not be as popular or as widely available in various forms as is its larger optical rivals, we root for the single barrel optic.
For everything from low prices to high power and specialized features such as night vision and thermal monoculars. From both underdog and authoritative brands, we've got a monocular up our sleeve that you will want to know about before you buy!
Our 13 Top Monoculars Compared
|Roxant Grip Scope||CHECK PRICE|
|Wingspan Optics Titan 12X50||CHECK PRICE|
|Emarth Tech Zoom 10-30X50||CHECK PRICE|
|Bushnell Legend Ultra HD||CHECK PRICE|
|Leica Monovid 8X20||CHECK PRICE|
|Vortex Solo 10X25||CHECK PRICE|
|Zeiss Mono 6X18 T||CHECK PRICE|
|Celestron Nature 10X25||CHECK PRICE|
|Vortex Recce Pro HD 8X32||CHECK PRICE|
|Gosky Titan 12X50||CHECK PRICE|
|Carson CloseUp 6X18||CHECK PRICE|
|Zeiss 5X10 T MiniQuick||CHECK PRICE|
|Firefield Siege 10X50||CHECK PRICE|
A lot of unexpected brands have earned a head start in our lineup as our top monocular recommendations. Why? Believe it or not, most buyers are ordinary people who want something affordable, portable, easy to use, and works without issue.
Not every buyer is out to spend a fortune on an expensive setup. Not every buyer is an obsessed bird watcher, the seasoned, light-packed hunter, or an undercover law enforcement agent. But, if you happen to be on the lookout for a high-end monocular for these specialized reasons, we've got you covered here too.
Most likely, this one monocular will be used for everything from observing far-off wildlife to enjoying the touchdown moment at a game. At the same time, you can consider a monocular for hiking, sightseeing, camping, stargazing, hunting, and even covert operations that those in law enforcement and the military would be involved in.
Most monoculars in our lineup are intended to be used as stand-alone devices. The thing about monoculars is, they're easily portable and convenient to use. They shed the weight of similar spec binoculars, and their handheld use in a compact and lightweight package is the biggest advantage of all.
Whether it's a budget restriction, hunting need, or compact design that drives your shopping criteria, we have a recommendation for you.
Top 13 Best Monocular Reviews
1. Roxant Grip Scope Review - Best Budget Monocular
- NO SLIP COMFORT MOLDED GRIP - Provides Less Shake - Very Easy To Hold Steady With One Hand - We’ve combined the best of comfort and functionality meaning you can...
Roxant has mastered the art of producing a limited amount of affordable, quality products that hit home with the buying crowd. One such product is the Grip Scope monocular that has several hundreds of buyers and a proven track record behind its name. As an inexpensive scope, can it really be the bargain it's intended to be?
- No-slip grip
- BaK-4 glass
- Retractable eyepiece
- Focusing issues
The Grip Scope is a compact, mini device and has a lot going for it. It's obviously a bargain buy for its low price, and we recommend it to make camping, bird watching, and possible spy sessions even more fun.
Even though it's basic and has entry-level quality, it has quality features worth mentioning. As a 6x30 monocular, it's just compact enough to forfeit the process of having a retractable eyepiece, but Roxant doesn't cut corners. Instead of cheap, fold-up types that never stay up, they install a twist-up eyecup to help the user achieve ideal eye relief with or without glasses. By the way, actual eye relief is a long 20 mm.
BaK-4 glass makes up the prism assembly and air-to-glass surfaces are finished with fully multi-coated coatings. A focus rings allows you to adjust the monocular to get the sharpest, best sight picture possible. As for its "wide view" claims, the Roxant monocular actually lives up to its claim. Field of view is 180 m at 1000 m which is pretty darn good for a monocular.
However, there are many buyers that are using the retractable eyepiece incorrectly or mistakenly assuming it's the focus mechanism. This has caused a lot of confusion in being able to properly focus the monocular. It might pay to peruse the easy-to-read instructions before labeling the Roxant as a defective optic.
Considering the Grip Scope is under $100, is compact, and has a very versatile design, it certainly earned its place as top monocular in this lineup!
2. Wingspan Optics Titan 12X50 Review - Best Monocular for the Money
- The most powerful 12x50 monocular on the market: It's no wonder thousands of wingspan customers acknowledge its power by calling it the best monocular in the market...
If you didn't already know, this well-loved outdoors company was recently rebranded as Wingspan Optics as they brought out a new product line and shut its doors to their former name, Polaris Optics. Why the change? As Wingspan Optics, they're now better equipped to focus on producing industry-leading monoculars specifically for the avid bird watcher. The Titan is a plunge forward in this vision to offer the highest quality optics to bird watchers of all types.
- High magnification
- Tripod mountable
- DiamondBright technology
- Narrow field of view
The Titan is specifically designed to bring high power and extreme detail in one, highly-portable package for the fanatical birder. With 12x magnification, it tops the high end for monoculars, and with a 50 mm objective lens size, there's a lot of potential to get the brightest picture to enjoy the colors and details of your winged friends.
It seems the Titan is the only product currently that has the brand's DiamondBright Structural Optics technology. While it's not entirely clear what this tech is, we're certain it's the BaK-4 prism, an improved structural system, and fully multi-coated optics.
The Titan is fully outfitted to be drop and shock proof with its DuraArmor rubbered body. It's also been nitrogen-filled to be fogproof, and it's waterproof to keep you out when the weather isn't exactly on your side.
As a quick side note, the Titan is the upgraded model of the Explorer. It has a few more accessories and an improved optical structure.
We should mention that with high power optics you will always sacrifice field of view. With only 82 yards (246 ft) at 1000 yards, it's narrow to begin with and it may be difficult to see the entire scope of it with only 14 mm of eye relief. If you don't wear glasses, then you'll have less of a problem with these specs.
If you have any issues with it, which isn't the trend, you can always take comfort in knowing the Titan is covered with a Lifetime Warranty with a replacement guarantee. Buying from Wingspan is buying with confidence.
3. Emarth Tech Zoom 10-30X50 Review - Best Zoom Monocular
- ✅【Portable Zoom Monocular 】- Emarth monocular features a powerful zoom magnification range that adjustable 10x to 30x magnification, use low magnification if you...
This zoom monocular is a new product for the brand, and it's already hitting trend-setting ratings with the masses. As a variable power handheld scope, you can imagine the convenience and benefits it will bring to your next hunt, bird watching session, or safari adventure.
- Zoom power
- Good eye relief
- Fully multi-coated
- IPX7 rating
- Narrow field of view
High quality zoom monoculars are tough to produce. With that said, you will not find a high-end zoom optic save it be a full-size spotting scope with a very high price tag. If you're after the variable power of a cheap monocular for purely recreational purposes, the Emarth 10-30x50 monocular may be for you.
Although field of view will be seriously compromised (71-35 m @1000 m), buyers have said the Emarth scope is capable of reaching 30x zoom. Since the monocular is compact at 8 x 4 x 3 inches and is lightweight weighing in at 1 pound, it may pay to mount it to a tripod with the 1/4" connection for an extra steady image when you don't want to miss a thing.
Fully multi-coated optics, BaK-4 Porro prism, a large 50 mm objective lens diameter, and 15.4 - 19.5 mm eye relief puts it on par with other decent monoculars in this price range. It's at the top of its game in the field, and will be a nifty gadget to have the next time you need an up-close view.
Thanks to its low price tag, comparable quality to other similar monoculars, and its fast-growing popularity with the masses, the Emarth Tech Zoom monocular has earned its place with us.
4. Bushnell Legend Ultra HD Review - Best Monocular Under $200
Bushnell has an optic inventory that can cater to every type of outdoor enthusiast and tactical agent there is. Of course, there is a monocular from this well-known brand that makes it into our lineup. The Legend Ultra HD monocular has trusted optics, multiple features, and specs to suit almost every buyer that needs a durable and sharp set of eyes.
- ED Prime glass
- PC-3 Phase Coating
- Ultra Wide Band Coating
- RainGuard HD
As you can see, the optics on this monocular are impressive. To start with, it has a roof prism assembly with BaK-4 glass that includes ED Prime (Extra-low Dispersion) elements to provide HD (High Definition) image quality.
But, a roof prism optic wouldn't mean much if the process wasn't complete with PC-3 Phase Coating technology. What is it? It's a special coating that gets applied to the prism to improve contrast and resolution.
Ultra Wide Band Coating tech is exclusive to Bushnell. It consists of applying 60 layers of coating on the prism assembly to ensure maximum light transmission for the brightest picture you can possibly achieve.
As is expected of Bushnell, RainGuard HD protects the integrity of your sight picture and the outer lens from weather. Speaking of weather, it's also fog and waterproof with an IPX7 rating. Features don't end just yet as it also has twist-up eyecups, a focusing knob, and a Picatinny rail and carry clip to allow mounting.
It's a high power monocular with 10x magnification and a 42 mm objective lens, and it's half the weight and half the price of a 10x42 binocular with the same features. Regardless, it's more expensive than other monoculars on the market as you're paying for the significant improvement in image quality and the security of buying from a well-known trusted brand backed with their Ironclad warranty.
5. Leica Monovid 8X20 Review - Best for Surveillance
We promised we'd throw in a high-end monocular from a premium brand for you serious buyers out there looking for the highest scope quality possible. What better brand could we pick than Leica? The Monovid 8x20 may be small, but its big reputation precedes itself. With a price tag that is more than quadruple what we're seeing in the lineup, is the Monovid all that it's cracked up to be?
- 8x magnification
- Extreme close focus
- HDC/AquaDura coatings
- Aluminum housing
We all know Leica optics are expensive - it's the tradeoff for high quality materials and superior image quality not seen on other optics. Regardless, when you want the best, you're willing to pay for it, and Leica is a brand we recommend putting your money with all day, every day.
An aluminum housing keeps the monocular extremely durable and lightweight. Since this is a Leica, it's not just waterproof in a generic kind of way, it's water-tight and submersible to a depth of 5m. To protect air-to-glass surfaces, AquaDura and HDC (High Durable Coating) coatings are applied for the best viewing and protection you can have when out in harsh weather and terrain.
The Monovid has an impressive close focus distance of 1.8 m, but if you need painstaking detail when you're already up and close, you'll want to take advantage of the included close focus lens. With this attachment, a close focus distance of 25-30 cm is easily achievable.
Since this mini scope has Leica quality behind it, it's the best monoculars for tactical scenarios or surveillance when industry-leading contrast, color fidelity, and resolution is needed to make out minute details.
Only the hardcore spenders are going to consider the Monovid. How obsessed are you?
6. Vortex Solo 10X25 Review - Best Monocular for Hunting
We heartily welcome a Vortex optic to the lineup, and the Solo 10x25 model is the pick of the lot. Vortex has easily been a first choice brand for many as their VIP warranty is famously known to be true and honored. You can spend less than $100 and still be guaranteed the best valued monocular on the street.
- Fully multi-coated
- Rubber armored
- Stiff focus ring
The Solo is the only monocular you'll ever need to buy. It'll put you at the top of the food chain with its high 10x power to get you seeing further and its fully multi-coated optics to get you seeing brighter.
However, let's be real for a second as it only has a 25 mm objective lens. It's not going to perform in lowlight conditions like a pair of 10x42 or 10x50 binoculars would. But, for instant spotting in multiple hunting situations, the Solo can get it done for you just like it has with its satisfied following of disciples. So, leave the binos behind if you truly want a pocket-sized set of eyes.
An adjustable eyecup allows use for those sporting spectacles, however, the eye relief is still pretty tight with only 14.5 mm of leeway. With Vortex behind its build, you know it’s both fog and waterproof and wrapped in a durable rubber armor for ultimate shockproof protection.
A stiff focus ring might raise an eyebrow or two, but it shouldn't feel like it's welded to the build. Good thing it's a Vortex and it's backed with a VIP warranty, right?
7. Zeiss Mono 6X18 T Review - Best Under $500
- Zeiss T* Anti-Reflective coating is designed to reduce surface reflections and, consequently, remove flares and ghost images, resulting in a clear, crisp picture
- Field of view: 120m at 1000m away
- 6x magnification in a pocket-sized device
- Achromatic lens design minimizes chromatic and spherical aberration
Zeiss regularly comes up at the top of everyone's list when it comes to sport optics. They're an authoritative brand that has earned their stripes when it comes to industry-leading products. But, when buying optics from such a brand, prices may be just out of reach for most on the hunt for a monocular. The 6X18 T has a lot of offer, but are you willing to flip the bill for one?
- Extremely compact
- Extremely lightweight
- Schmidt-Pechan prism
- Extremely close focus distance
- Wide field of view
The Zeiss monocular is slim and sleek - an iconic feature for the German brand. It's only 3.7 inches in height and weighs only 2 ounces. It gives a whole new meaning of compactness when you're looking to ditch the weight and increase stealth and covertness.
Its highlight feature is its extremely close focus distance of just 30 cm. It's more akin to a magnifier than anything. This is an ideal feature for those with low vision or who are looking to scrutinize the details of fine art at a museum.
At the same time, it's also a high-quality, long-viewing, miniature telescope. With 6x magnification, you still have a great field of view range of 120 m at 1000 m. The mini mono isn't looking so mini now after all, right?
Because this is a "T" model, it has Zeiss' patented T* anti-reflective coatings to boost maximum light transmission for the brightest sight picture this 6x18 monocular can attain. Protect your investment with the included soft leather pouch. Carry it around with the included carry strap too.
The monocular is designed to be portable, convenient, and superior in optical quality to all else on the market. It does exactly as it's designed and advertised to if you can afford it.
8. Celestron Nature 10X25 Review - Best Under $50
Ultra compact. High power. Perfect for nature chasers and outdoor enthusiasts. That sums up the Celestron Nature monocular that's pocket-ready to be taken anywhere and everywhere at a moments notice.
- High power
- Twist-up eyecups
- Rigid focus ring
The Nature monocular is not a kid's toy. In fact, it's specifically stated by Celestron to be used by persons aged 13 and over, and it's designed to bring years of happy usage for the buyer. So, what kind of quality should you expect for such a cheap, mini gadget?
The Celestron monocular has multi-coated BaK-4 roof prism optics. This is indicative of entry-level quality which is exactly what you may want for a leisurely stroll or short people-watching session. Don't expect more than 100 yards of field of view and short 14 mm eye relief.
But, the little Nature unit is still a convenient device to have on hand. It's only 4.4 x 2 x 1.3 inches in size - truly pocket-sized for on-the-go convenience at any time. It's extremely lightweight at only 6 ounces - it barely weighs anything.
Twist-up eyecups are a bonus feature on this small monocular, and the rubber armor is deeply grooved for body protection and to provide a secure gripping surface. The very stiff focus ring is the only legitimate complaint reported. It may be a personal preference to avoid this, or a medical condition like arthritis would demand that you look for something else.
For most buyers, it's a fun monocular to have on hand for a range of applications. We say buying the Nature monocular for all your nature needs is a win-win situation.
9. Vortex Recce Pro HD 8X32 Review - Best Under $300
Everything tactical is what the Recce Pro HD monocular is about. It's a drool-inducing unit for the shooter who's after sub-MOA groups and high-precision accuracy. With a Mil-based reticle, ranging silhouettes, and ED glass, you could be a sharp shooter in no time.
- ED glass
- XR coatings
- Ranging reticle
- Folding eyecups
Let's face it: the more tech and quality an optic has, the more it's going to cost you. Some features such as ED (Extra-low Dispersion) glass that can provide HD image quality is sure to push a price tag way beyond that of a mediocre monocular on the market. If you want the better quality, be willing to pay for it.
The ED glass minimizes the effects of chromatic aberrations and enhances resolution for crisp and bright viewing that you demand from a premium monocular. Vortex also coats the optics with XR Fully Multi-Coated anti-reflective coatings to push light transmission rates above par.
The hash-marked MRAD reticle allows for windage, holdover, and ranging calculations. The reticle display also has multiple silhouettes for quick ranging. Get your reticle as sharp and black as possible with the reticle focus that is separate to the focus ring.
Unfortunately, we can't brag about the flared eyecup with its folding design. We've never been a big fan of fold-up eyecups, and it's a shame to see it on this high-end device. However, the integrated utility clip that's also compatible with the included MOLLE/PALS compatible pouch might be enough to get over it. You tell us.
10. Gosky Titan 12X50 Review - Best to Use With Smartphone
- 12X50 High Power Magnification Monocular Telescope- Have the best view in your outdoor adventures. To see 12X closer with a clear and bright image with the generous,...
- Comes with a Gosky 2020 newest quick alignment smartphone adapter mount. Compatible with phone Xs, X, Xr, 8plus, 8,7plus, 7,6, 6s, 6plus, 5, 5s, 4s,SE, Samsung GALAXY...
Titan - it's a popular name for a monocular, maybe because it represents a behemoth amount of features and quality for an ironically small device. While we've already seen a featured Titan in this lineup, the Gosky monocular has something else to offer. Let's check it out.
- Smartphone capability
- High power
- BaK-4 glass
- Quality control issues
Its most standout feature has to be its smartphone capability. The Titan is equipped with Gosky's newest quick alignment smartphone adapter. It's compatible with most iPhone, Samsung, LG, and more smartphone brands in the market. Hook it up and get ready to bring out your inner photographer skills.
With high 12x magnification and a large 50 mm objective lens, your ability to capture images and watch wildlife in low light conditions is dramatically improved versus 6x monoculars. While it's surprisingly compact at 2" x 3" x 5" in size and 14 ounces in weight, it should be mounted to a tripod to get the best and most steady image quality possible.
BaK-4 glass makes up the roof prism assembly in the mini spotting scope which has a higher light transmission rate than BK7. With fully multi-coated optics, twist-up eyecups, and a completely sealed and nitrogen-filled build, you have a monocular that's made to last, is easy to use, and will provide good photos anywhere, any time.
But, there are various quality control issues to be on the lookout for when you buy a monocular with a ton of features for such a low price. Make sure to fully inspect and test out your monocular upon box opening. Gosky customer service seems very responsive and eager to remedy any potential issues. Their products wouldn't be this popular if they weren't!
11. Carson CloseUp 6X18 Review - Best Compact Monocular
Monoculars don't get smaller than the Carson CloseUp. It's not just a small monocular, it's a tiny thing that takes being portable and on-the-go to a whole new level. To match its miniature design is a ridiculously low price. Is the CloseUp a joke or a toy? It's neither.
- Extremely compact
- Extremely lightweight
- 10" close focus distance
- Simple to use
- Quality control issues
The CloseUp, as mini as it is, is a real monocular. It has real glass with fully coated optics, 6x magnification, and an 18 mm objective lens diameter. While the field of view isn't too impressive for a 6x monocular, it still offers almost 150 yards at 1000 yards.
This compact monocular redefines scaled-down dimensions with its 3" x 1" x 1" (approx.) size and 1.6 ounce weight. It's not only smaller in size, it also has microscopic ability with its 10" close focus distance.
You can literally have the Carson monocular in your pocket at all times and even forget it's there. Low vision reading, hiking, sight-seeing, and camping are all great uses for this small device, but we wouldn't say it's good enough for tactical or hunting use.
With various issues reported including focusing difficulty, it's a relief to know you're buying from a trusted brand. Carson customer service reaches out to the masses about any issues they may have, and we can attest to the quality of their customer care.
The CloseUp, as its name suggests, is an excellent low vision monocular for getting up close and personal for microscopic views. For that reason alone and the fact that it's so darn cheap, it's more than worth the buy.
12. Zeiss 5X10 T MiniQuick Review - Best Ultralight Monocular
It's not unusual to see Zeiss take up many spots in various lineups across the board. They've certainly done it a time or two with us. Another Zeiss optic to take the honors of a place in our best-rated monocular lineup is the 5x10 MiniQuick monocular. If you want a take-it and forget-it type of gadget on you at all times, there is no other option for you than the MiniQuick.
- Extremely lightweight
- Schmidt-Pechan prism
- T* anti-reflective coatings
When Zeiss says the MiniQuick is as light as a feather, they're not exaggerating. It doesn't even weigh an ounce. It might be 4.4 inches tall, but it looks just like a pen. In fact, an included clip is thrown in with the buy that you can actually use to clip it to your shirt pocket just like you would a pen. It's almost ridiculous how deceiving this monocular can be.
The increased covertness and stealth you have from using this smaller and unobtrusive monocular will provide instant and quick use in the moments you need it most. With T* anti-reflective coatings, your sight picture is still bright as can be for a 5x10 optic.
Surprisingly, the Zeiss monocular isn't as structurally sound as its other high-end cousins in the optics market. You don't want to drop this device, squeeze it too hard, or expose it to extreme weather conditions. But, since it's a Zeiss, you know it's covered with multiple types of warranties.
No one buys a "pen" for $200, but you will for a monocular that looks like one. Being the ultimate spy means spending some decent moolah.
13. Firefield Siege 10X50 Review - Best Monoculars for Stargazing
Firefield is a busy brand that has been working tirelessly to manufacture high-quality optics for a fair price. They're typically geared towards everything tactical, but they’re also known as an established brand in the night vision hunting world. While the Siege monocular isn't a night vision monocular, it is an optic that we say would be a great asset for stargazing. It's not a device that's not well-known, but we recognize its quality and benefits it brings to the field and open skies.
- 10x magnification
- BaK-4 prism glass
- Tripod mountable
- Twist-up eyecup
- No buyer history
The 10x50 specs of the Siege monocular provides long-range viewing, no matter the distance, for longer periods of time. It's a high powered, large aperture monocular that can keep you out later as dusk approaches. This is an excellent feature for hunters and law enforcement/military that need the cover of twilight to stalk their prey.
As far as stargazing goes, the high power is worth the sacrifice in field of view when you have a darker background and increased detail when finding constellations, double stars, and vast galaxies. While it can be tripod mounted for an extra steady image, it’s the lightweight and compact size that gives it an edge over 10x50 binoculars. It's small enough to be taken along anywhere without fuss.
Hiking and stargazing with the Siege monocular is right up its alley. Again, it's high-powered enough to see crags and pathways during the day and celestial bodies at night. With BaK-4 prism glass, you have a rounded exit pupil of 5mm that is better than the squarish appearance of BK7 glass.
Fully multi-coated optics help to transmit as much light as possible through the mini scope to the eyepiece. A retractable eyepiece is definitely a bonus feature to see on a monocular this cheap.
While we've rebranded the Siege monocular as an excellent, small instrument for stargazing, it has the same great specs and features to be out when deer and villains are most active. As a multi-purpose monocular, the Firefield optic has won us over.
What to Look For in a Good Monocular
The obvious features relate to size. It must be small enough to be portable and convenient, but it should have usable specs that make it a worthwhile optic.
Whether you need a monocular for travel, hunting, surveillance, or just to read the text on a billboard, you'll need to keep some main features and considerations in mind.
The best monocular will be inherently compact and lightweight optics. This is their primary benefit as they are excellent portable and handheld devices. Larger and heavier monoculars will weigh in around 16 ounces and more, and they can even rival compact spotting scopes in size. However, the most compact monoculars can be as slim as a pen and no longer than your index finger, but many will range around 8 ounces in weight and 4-5" in height.
There are a lot less moving components and glass elements in a monocular versus scopes and binoculars, but a monocular still requires attention to optical quality. While high-end monoculars are rare, the best will have ED/HD elements, specialized prism coatings, and protective external coatings. Monoculars worth buying should have nothing less than fully multi-coated optics as it is easily affordable and should be considered standard quality.
The type of eyecup or lack of one on your monocular may not seem like a big deal until you try to use it. Because monoculars are small, some manufacturers don't install a retractable eyecup at all. This is unfortunate. Eye comfort and relief have a lot to do with the type of eyecup. Twist-up/retractable is the best.
If you can't see the entire field of view, you may not have enough eye relief. Forgiving eye relief is around 20 mm and is ideal. 15 mm is desirable at minimum for those who wear glasses.
Field of view is the measured distance of an area you can see through the monocular at a given distance which is usually 1000 m/1000 yards. Lower power monoculars will have the widest field of views (aperture must also be considered). 180 yards is very high for a monocular. 100-140 yards is good and is standard.
High power means you can see more, but it's only effective if you have a steady hand or are able to mount to a tripod to stabilize the image. 10-12x is the high end for a monocular. You will also sacrifice field of view.
Low power monoculars are between 5-8x. They have wider field of views, but some 5x and 6x models are often combined with small apertures of 18-25mm which reduces overall brightness as they're more suited for inside use, low vision, and magnifying benefits.
The debate between which is better is endless as it's completely subjective. While a monocular is essentially just one barrel of a binocular, they have different advantages to a user. Primarily, a monocular is easier to use as you only have one barrel to focus and look through. It's also much more compact and lightweight than a bino. For the same specs and quality, monoculars are also cheaper.
Buying the most appropriate monocular for your needs means being activity specific. A high-powered, large aperture monocular may be great for hunting or wildlife observation but would not work well for someone using it to magnify text while reading.
Some specialized monoculars may be more weatherproof and durable for outdoor or combat use, and others may have reticles to aid tactical and shooting scenarios. However, monoculars make great all-purpose optics for many observation activities.
Monoculars Are Small But Mighty!
The monocular is one of those small instruments that everyone forgets about until they need the convenience of big benefits in little things. They are extremely helpful for multiple situations you will inevitably find yourself in, be it travel, enjoying the outdoors, or even stargazing.
Don't underestimate the power or convenience of having the right monocular for your intended purposes. They may be small, but they make all the difference in the world.
Don't leave your eyes naked and unaided!