What Causes Bad Eyesight? 10 Reasons
January 23, 2025 • 8:27 PM
If you want to take the best possible care of your eyes, you need to know the most common causes of bad eyesight.
In this post, we’ll take a look at some of the factors that can make a person’s vision worse, including aging, eye diseases, and more. We’ll also give you some helpful recommendations for keeping your eyes healthy and your vision as close to 20/20 as possible throughout life.
What Causes Bad Eyesight? 10 Reasons
Below, we’ve put together a list of some of the most common causes of bad eyesight.
As you can imagine, some are preventable, while others are just natural parts of life. While you can’t avoid certain causes of bad eyesight, there are still steps you can take to protect your vision, which we’ll cover before we wrap up.
1. Your Genetics and Family History
Vision problems often run in families, which means you can thank your parents (and grandparents, great-grandparents, and so on) for needing glasses. Common eye conditions like nearsightedness (myopia), farsightedness (hyperopia), and astigmatism are hereditary — they’re passed down generationally.
The best way to deal with the genetic aspect of bad eyesight is to get regular eye exams. Your eye doctor will get a comprehensive readout of your eye health every time you visit, which can help them detect the early signs of inherited eye conditions as soon as possible. That way, you can start correcting your vision with glasses or contact lenses if needed.
When you visit your eye doctor, let them know if any eye diseases, such as cataracts or glaucoma, run in your family. If so, your optometrist will most likely monitor the parts of your eye where symptoms of these diseases manifest, including the retina and cornea.
2. Your Age
Age-related eye problems are a sad fact of life. Unfortunately, most adults typically develop some level of presbyopia in their 40s, a condition that makes it harder to focus on close-up objects.
In addition, cataracts and age-related macular degeneration are very common causes of poor eyesight in older people. Since these conditions are often natural parts of the aging process, they cannot be avoided completely.
However, living a healthy life can set you up for a lower risk of aging-related vision loss. Eating a diet rich in antioxidants can be helpful, as can visiting your ophthalmologist regularly. Ultimately, though, your eyes are likely to get worse with age, which might mean you end up needing eyeglasses (at least to read) later in life after years of decent vision.
3. Screen Time and Digital Eye Strain
We use our digital devices all the time, whether we’re working, relaxing, or just trying to stay connected with the people we love. There’s nothing wrong with technology — it’s a blessing — but looking at screens for too long can cause worsening vision over time.
The best way to reduce your risk of developing screen-related vision issues is to take breaks from the computer, smartphone, and other digital devices as often as possible. Ideally, look away from your screen every 20 minutes, focusing on something at least 20 feet away for 20 seconds or more (also known as the 20-20-20 rule).
Thankfully, many big tech companies are recognizing the role of reducing screen time in a healthy eye care routine. For example, Apple recently added a feature to the iPhone that lets you know when you’re holding its screen too close to your face. You can enable this handy feature in Settings.
4. UV Light Exposure
Too much direct exposure to the sun’s rays can cause poor vision over time and can even increase your risk of cataracts. UV rays may also lead to the development of a painful condition called photokeratitis — corneal sunburn. That’s not something you ever want to deal with, and it can affect your vision permanently.
The best way to protect your eyes from UV rays is to wear sunglasses. Ideally, your shades should block out 100% of UVA and UVB rays while still giving you clear vision. Polarized lenses are the best option by far; they filter out UV rays and block glare, making it easier to see in bright sunlight.
If you’re looking for a new pair of sunglasses, the Pair Eyewear shop is the perfect place to start. Our Sun Tops pair seamlessly with our signature Base Frames, transforming your everyday eyeglasses into your new favorite pair of shades. You can experiment with different styles using our virtual try-on feature.
5. Eye Injuries
Any type of serious eye injury can cause long-term issues like blurred vision and refractive errors, especially if parts of your eye are seriously damaged. While this isn’t one of the most common causes of poor vision, it is a real concern that you should always take steps to avoid.
To stay safe and protect yourself from eye injuries, always wear personal protective eyewear (PPE) whenever you’re doing dangerous work. This includes heavy-duty tasks like using power tools, but it also applies to mowing grass or using powerful cleaning chemicals. You might not think that PPE is necessary for these tasks, but it’s worth it to protect yourself as much as possible.
If you do get any type of eye injury, make sure to contact your doctor right away. The longer an injury goes untreated, the higher your risk of an infection or long-term vision impairment.
6. Eye Infections
Viral, bacterial, and fungal eye infections all need to be treated immediately to avoid long-term vision loss. Even pink eye, a very common and contagious infection, can hurt your vision in the long run by causing long-term inflammation and even scarring.
If you have symptoms of an eye infection, including itchiness, redness, swelling, orand discharge, head to your eye doctor’s office for a comprehensive eye exam right away.
In addition, always take steps to avoid infections, like washing your hands before touching your eyes, not sharing makeup brushes or face towels with anyone (even your spouse or partner), and flushing out your eyes with water anytime something irritating comes into contact with your eyeball.
You might be at a higher risk of eye infections based on environmental factors in the place where you work or live. For example, if you’re a carpenter and send sawdust flying on a daily basis, always make sure to wear personal protective eyewear; irritants like sawdust and wood pieces can cause an infection if they get in your eyes.
7. Not Getting Your Eyes Checked
Regular eye exams are a must to keep your vision as strong as possible throughout your life. Ideally, you should visit your eye doctor at least once a year and get a comprehensive exam, including screening for common diseases like cataracts and glaucoma.
Many of the most common eye problems, including nearsightedness, farsightedness, and astigmatism, develop very gradually, which means you might not notice your eyes getting worse unless you get insight from your eye doctor. That’s why we always recommend sticking to a consistent schedule of exams, even if you’re busy!
8. Glaucoma
Glaucoma is a disease that damages your optic nerve, which can cause blurry vision and overall vision loss over time. It’s usually caused by increased eye pressure, which can be linked to other diseases.
Sadly, there’s no cure for glaucoma, but the sooner you get treatment, the sooner you can stop the disease from progressing. Doctors often recommend treatments that lower eye pressure, including beta-blocking eye drops.
In most cases, your eye doctor will refer you to an ophthalmologist to get treatment for glaucoma. An ophthalmologist specializes in eye diseases and is qualified for eye surgery — which is sometimes part of the treatment plan for a disease like glaucoma.
9. Cataracts
Cataracts are a common eye condition that can cause symptoms like blurry vision, limited peripheral vision, and more. They can also change the way your eyes look, creating a clouded effect as they progress.
Unfortunately, cataracts are a natural part of the aging process for many people, but their progression can be prevented or slowed with early diagnosis and treatment. If you notice your vision getting worse or changes in how your eyes look, talk to your eye doctor.
10. Diabetes
Diabetes can affect your vision as the disease progresses, especially if it isn’t treated promptly and properly. If you’re diabetic, work closely with your optometrist and primary care doctor to develop a comprehensive treatment plan.
How Can You Protect Your Eyesight?
Age, genes, and other uncontrollable factors can worsen eyesight, especially over time. Luckily, though, you can still be proactive and adjust your lifestyle and habits to keep your eyes healthy.
These are some of the best ways to protect your eyesight in your day-to-day life.
Get Consistent Eye Exams
Your eye doctor is the core of your vision support system. They want your eyes to stay healthy and see clearly for as long as possible. With that said, there’s nothing they want more than for you to show up to your eye exams!
Sticking to a consistent schedule of eye exams helps your eye doctor get a clear sense of the best way to support your eye health. During a routine exam, your optometrist will check your vision for changes, update your eyeglasses and contact lens prescriptions, and screen for common eye diseases like glaucoma and cataracts.
In addition, your eye doctor is always there to answer any questions you have about eye health. Whether you want to learn how to take better care of your eyelashes or what to do if you get pink eye from your third grader, your optometrist can help.
Ideally, you should schedule an appointment with your eye doctor at least once per year. Twice a year may be even better, especially if you have been diagnosed with an eye condition.
Take Breaks From Screens
We know that overusing digital devices like smartphones and laptops can hurt our vision over time, but it can be hard to limit the amount of time we spend using tech. However, a little bit of moderation can go a long way in preserving your eye health.
As a general rule, it’s best to spend no more than 20 minutes looking at a screen before taking a break. During your break, try to focus on something far away. As we mentioned earlier, the 20-20-20 rule —look at something 20 feet away for 20 seconds after 20 minutes at a screen —can be a helpful point of reference here.
Protect Your Eyes From the Sun
As we already discussed above, sun damage is one of the most common causes of poor eyesight over time. Even a habit as simple as wearing a pair of polarized sunglasses can make a big difference, especially if you spend a lot of time in bright sunlight.
Make Eye Health a Priority
Now that you know some of the most common reasons why vision gets worse over time, it’s time to make some changes to protect your eyesight.
Start with getting regular eye exams — and replacing your old glasses and contacts with your new prescription. From there, you can take good care of your eyes by protecting them from the sun, limiting your screen time, and more. It’s a bit of work, but it’s worth it.
Sources:
Types of Vision Problems | Health.NY.gov
Cataracts - Symptoms and causes | Mayo Clinic