An excessively curved cornea, meanwhile, looks exactly as you picture it. The cornea is too steep or has a deeper curvature than normal.
When an eyeball is too long or the cornea is excessively steep (or both), the eye bends light at a much sharper angle than required. Consequently, the eyes focus light in front of the retina instead of on the retina.
Do You Have Myopia?
You can get your eyes examined by an ophthalmologist to know for sure, but here are the symptoms of myopia:
- You have trouble seeing faraway objects clearly.
- You typically need to squint to adjust your eye focus.
- You frequently experience eye strain.
Is Myopia Hereditary?
Note that children of parents with myopia may have a higher chance of being diagnosed with it themselves. However, the way people use their eyes can lead to the development of the condition.
A study published in the American Academy of Ophthalmology suggests that near-work activities (e.g., reading books, watching videos on mobile screens) and reduced time spent outdoors increase the risk of myopia incidence among children.
Let this be a wake-up call. If your child is always indoors, reading a book or watching videos on his mobile phone, you should get his vision checked.
- Hyperopia
Hyperopia is the clinical term for farsightedness. This refractive error makes it easy to see things that are far away but difficult to see nearby objects.
It is typically caused by the following:
- Short eyeballs
- A relatively flat cornea
You have short eyeballs if the distance between the front and the back of the eyeball is shorter than normal. Thus, a cross-section of the eyes will show the eyeball being vertically oval-shaped instead of round. It is oval, but it looks squished, so the eyeball seems taller than it is long.
Meanwhile, you have a relatively flat cornea if your cornea has a slight curvature than is ideal.
When your eyeballs are too short or your cornea too flat (or both), the eyes bend light at a much milder angle than normal vision requires. Consequently, they focus light behind the retina instead of on it.
Do You Have Hyperopia?
If you have these symptoms, you may have hyperopia:
- You have trouble focusing on nearby objects.
- You suffer from headaches, especially when doing near-work activities like writing and reading (whether printed material or something on a screen).
- You frequently suffer from eye strain.
- You have to squint to adjust your focus.
Is Hyperopia Congenital and Hereditary?
Hyperopia is primarily a congenital condition — i.e., present from birth. It is typically hereditary, as well.
A refractive error similar to hyperopia can develop when a person reaches 40, but that is known as presbyopia.
Note: According to a systematic review and meta-analysis by Khoshhal et al., hyperopia has a relatively high prevalence rate among children in the Middle East, while myopia has a higher prevalence in adults.
If hyperopia runs in your family, visit a paediatric ophthalmologist in Dubai to check if your child has farsightedness and discuss treatment options.
- Presbyopia
Presbyopia is effectively an acquired, age-related form of farsightedness. It usually manifests among adults at least 40 years of age and makes them unable to see nearby objects clearly.
As a person grows older, the lenses of the eyes become more rigid or inflexible. Thus, they can no longer bend light as effectively as they could, so they end up focusing light behind the retina instead of on the retina.
Do You Have Presbyopia?
Only an ophthalmologist can tell you with certainty if you have this eye condition. However, almost everyone who is age 40 and older experiences some degree of presbyopia.
If you start experiencing or doing any or all of the following things (especially if the symptoms start after you turn 40), you might have presbyopia. Even if it’s not presbyopia, you should set an appointment with your eye doctor if any of the following apply:
- You have difficulty reading nearby materials.
- You have difficulty seeing things up close.
- You squint when focusing on nearby materials and objects.
- You hold something farther away to see it clearly or to read it.
- You need to hold your mobile phone at arm’s length or farther away to read or see what it says.
- You suffer from headaches or eye strain after doing close-up reading or focusing.
Is Presbyopia the Same as Hyperopia?
You could say the symptoms of presbyopia are similar to hyperopia, characterised by clear vision on faraway objects and blurry vision on nearby objects. However, while they might manifest the same way, they do not have the same cause.
- Astigmatism
Astigmatism leads to difficulty seeing both nearby and faraway objects. It is caused by an imperfection in the curvature (i.e., unevenness) of the cornea or lens.
An astigmatic cornea can be taller than it is wide (i.e., vertical astigmatism) or wider than it is tall (i.e., horizontal astigmatism). Thus, it cannot focus or refract light properly.
Do You Have Astigmatism?
The following are the common symptoms of astigmatism:
- You don’t see things clearly or have selective vision distortion.
- You frequently suffer from headaches.
- You frequently suffer from eye strain.
- You have to squint to see clearly.
Diagnosis Is Crucial
Consult an ophthalmologist if you have blurry vision. It is even more crucial to get regular eye screenings for children.
Your child may not realise they have blurry vision until their vision is assessed. Left undiagnosed, astigmatism can affect their school performance and overall quality of life.
Refractive Errors of the Eyes
When you suffer from blurry vision, it is likely due to one of the four refractive errors: myopia, hyperopia, presbyopia, or astigmatism.
Myopia is near-sightedness, hyperopia is congenital farsightedness, presbyopia is adult-onset farsightedness, and astigmatism can cause both nearby and faraway blurry vision.
Whatever the cause of your vision problems, it’s essential to consult an eye specialist to get an accurate diagnosis and treatment.
AUTHOR BIO
Dr. Millicent M. Grim, Specialist Ophthalmologist & LASIK Specialist, is the Medical Director of the former Gulf Eye Center in Dubai. Since 2002, Gulf Eye Center’s highly qualified ophthalmologists and optometrists/ODs have been successfully treating a wide range of eye conditions using advanced techniques. They have recently moved to GULF EYE DOCTORS, and also provide comprehensive eye care and vision restoration procedures for people of all ages.