Astigmatism is a common vision condition that causes blurred vision. It occurs when the cornea (the clear front cover of the eye) is irregularly shaped, causing light rays to focus incorrectly on the retina (the light-sensitive tissue at the back of the eye).
This results in distorted and blurred vision at all distances. Objects can appear stretched out, causing lines that should be straight to appear wavy or bent. Vision may be clearer in one direction compared to the other.
Astigmatism affects around 1 in 3 people globally. It can be present from birth, or develop later in life. The severity ranges from mild astigmatism which causes only minor vision disruption, to severe cases that significantly impact day-to-day vision.
What is normal vision like?
People with normal vision, or emmetropia, can see objects clearly both near and far. Their corneas have a regular, spherical curve that enables light rays entering the eye to focus precisely on the retina.
Without astigmatism, vision has the following characteristics:
- Objects at any distance appear sharp and in focus
- Lines and edges appear crisp and distinct
- Reading is clear across the entire page
- Vision is evenly clear in both eyes
Normal vision provides sharp, undistorted images of the world. It allows you to recognize faces, read signs, and perform detailed tasks without eyestrain or headaches from visual fatigue.
Differences in vision clarity
The key difference between normal vision and vision with uncorrected astigmatism is clarity. Without astigmatism, sight is evenly focused in all directions. With astigmatism, certain lines and details look blurry or distorted.
Imagine looking through a clean, smooth glass window. Objects on the other side appear clear and distinct. Now imagine that same window with ripples and warps throughout the glass. Looking through it, objects become partially warped and blurred. Their edges and shapes are irregular.
This demonstrates the difference between normal vision and astigmatism. Uncorrected astigmatism casts a distorted irregular focus across your field of vision.
Differences in depth perception
Normal depth perception relies on your eyes working together to judge distances between objects. Slight differences between the two retinal images provides information about depth and position.
With uncorrected astigmatism, the irregular corneal curve results in different focal points in each eye. This can impair depth perception. Targets may appear closer or further than they actually are.
Most people adapt to mild differences in focal points between their eyes. But depth judgement can become more challenging as astigmatism increases.
Differences in field of vision
The field of vision simply refers to the total area you can see around you, including both central and peripheral vision. Uncorrected astigmatism typically does not restrict the field of vision. It affects clarity rather than field width.
However, higher degrees of uncorrected astigmatism can make objects around the edges of your field of vision appear very blurry or distorted. It becomes harder to interpret what you are seeing in your peripheral vision.
Vision at night
Nighttime vision may also be impaired with uncorrected astigmatism. Low light conditions already reduce visual clarity for people with normal vision. With astigmatism, blurry and distorted vision can become more pronounced at night.
You may experience:
- Starbursts and glare around bright lights
- Halos around objects like car headlights
- Impaired ability to drive safely at night
Many people with astigmatism find their vision at dusk, nighttime, or when driving is significantly improved with an appropriate prescription for glasses or contact lenses.
Reading and close work
Uncorrected astigmatism can make tasks like reading, writing, watching TV and working on a computer more challenging. Without clear vision, you may experience:
- Eyestrain and headaches during close work
- Difficulty reading small text
- Inability to read an entire page clearly
- Letters and words appearing to move on the page
Even mild uncorrected astigmatism can cause eye fatigue or visual discomfort when doing close-up tasks, due to working harder to see.
Distance vision
Seeing objects clearly at a distance becomes more difficult with uncorrected astigmatism. Signs, faces, and details on distant objects can appear fuzzy or indistinct.
You may have trouble:
- Recognizing faces from afar
- Reading road signs until very close
- Seeing objects at a distance as more than just a blur
- Playing sports that require seeing a ball or other players at distance
Uncorrected astigmatism affects vision at all distances. But the effects are often more noticeable when trying to focus on distant rather than very near objects.
Eye strain and fatigue
Squinting, concentrating, and working harder to focus vision usually leads to eye fatigue and headaches with uncorrected astigmatism. This eye strain is from the extra effort to achieve clear sight.
Symptoms may include:
- Headaches around the eyes and temples
- Tired, sore eyes after short periods of concentration
- Frequent blinking or rubbing of the eyes
- Dizziness or motion sickness from distorted vision
Eye strain from astigmatism can mimic symptoms of nearsightedness. But prescription glasses for myopia only will not correct the distortion caused by irregular astigmatism.
Misjudging distances when driving
Driving requires accurately perceiving distances between yourself and other cars, pedestrians, traffic lights, road signs, and other objects. Uncorrected astigmatism can make driving more hazardous if distances and spatial awareness are affected.
You may experience:
- Difficulty gauging the gap between oncoming cars when turning
- Misjudging the distance and speed of approaching vehicles
- Near collisions or running red lights due to blurred vision
- Lane position errors from inability to see lines clearly
Even mild uncorrected astigmatism could contribute to a car accident if it results in uncertainty about distances and position on the road.
Difficulty playing sports
Seeing a ball or other players clearly is key for most sports. Uncorrected astigmatism could make you less adept at sports requiring good hand-eye coordination and visual tracking ability.
You may have problems with:
- Hitting or catching a ball in sports like baseball or tennis
- Tracking and responding to moving teammates or opponents
- Judging distances on the field or court
- Seeing the ball after it is hit or thrown
Even with the best motor skills, distorted vision from astigmatism can affect overall sports performance. Corrective eyewear often improves ability.
Trouble recognizing faces
Making out facial features and expressions is more difficult with blurred or distorted vision. Uncorrected astigmatism may result in:
- Difficulty recognizing faces until very close up
- Appearing rude or unaware when unable to distinguish people
- Trouble discerning facial reactions and nonverbal cues
- Avoiding interactions with unfamiliar people
Face recognition is vital for social connections. Embarrassment over face blindness due to poor vision can lead to isolation and anxiety.
Impacts on work performance
Uncorrected astigmatism can affect work performance for jobs requiring:
- Reading papers, computer screens, or work orders
- Operating machinery or inspecting products
- Driving to meet clients or make deliveries
- Close-up detailed tasks like sewing
Reduced productivity or mistakes from blurred vision could jeopardize a job. Many occupations require vision correction for safety and efficiency.
Difficulty following moving objects
Tracking objects moving towards or away from you demands sharp focus at varying distances. Uncorrected astigmatism can make it harder to follow moving targets.
Challenges can include:
- Playing sports with balls or other moving objects
- Following your children on the playground
- Catching pets that get loose
- Avoiding oncoming cars when driving
The ability to accurately track object movement is essential in many daily activities. Vision correction often improves this visual skill.
Trouble executing visual tasks
Any undertaking requiring accurate hand-eye coordination can become more difficult with impaired vision. You may encounter problems with:
- Steps that require careful observation like giving injections
- Doing craftwork, sewing, or model building
- Assembling furniture from detailed instructions
- Following recipes, handling dangerous chemicals
Unclear vision slows response times to what you see, reducing dexterity and raising safety risks.
Heightened risk of falls and accidents
Blurred or distorted vision certainly increases chances of trips, slips, and falls in any environment. Hazards may go unnoticed, like:
- Cables or toys on the floor
- Wet or icy sidewalks
- Steps or curbs
- Tree roots on a walking path
With unclear vision, accidents can happen before the hazard comes into focus. Balance can also be affected by less acute depth perception.
Difficulty finding things
Routine visual searches become more tedious when objects lack clear edges and details. You may spend excessive time searching for:
- Your phone or keys around the house
- A specific file folder in the cabinet
- Your child in a crowded playground
- Products on cluttered store shelves
Everything seems to blend together when small differences are obscured by visual distortions. Life becomes less efficient.
Impaired ability to use tools
Safely operating tools and machinery is largely dependent on clear vision. Depth perception, hand-eye coordination, and visual precision are required for using devices like:
- Power tools, saws, and dangerous equipment
- Precision instruments like microscopes or electronics
- Artistic tools like pottery wheels or sewing machines
- Sporting gear like golf clubs, tennis racquets, or bows
Blurry vision raises risks of injury and impaired performance. Many jobs require corrected vision for proper tool use.
Trouble navigating new environments
The ability to quickly scan unfamiliar surroundings and see details clearly helps you safely navigate new places. Uncorrected astigmatism can mean:
- Bumping into objects or people in crowded spaces
- Getting lost more easily in complex buildings
- Avoiding new places for fear of disorientation
- Appearing rude or unaware when unable to see clearly
Navigating the world demands acute vision to take in spatial details, obstacles, patterns, and text rapidly.
SUMMARY TABLE
| NORMAL VISION | UNCORRECTED ASTIGMATISM |
|---|---|
| Clear vision at all distances | Blurred, distorted vision at all distances |
| Sharp vision field edge to edge | Very blurry peripheral vision |
| Easy, effortless reading | Eyestrain and headaches with reading |
| Crisp night vision | Impaired night vision with starbursts |
| Accurate depth perception | Impaired depth judgement |
| Easy facial recognition | Difficulty recognizing faces |
| Minimal eye fatigue | Visual strain and discomfort |
| Safe driving and navigation | Higher driving and fall risks |
Conclusion
People with normal vision unhindered by astigmatism can see the world with crisp clarity, excellent depth perception, quick recognition of faces and objects, rapid adaptation to varied lighting levels, minimal eyestrain, and accurate hand-eye coordination.
In contrast, uncorrected astigmatism can cause blurred or distorted vision, visual fatigue, impaired night vision, problems judging distances, and increased risks with driving, sports, or navigating environments. The extent of functional impairment spans a wide spectrum based on the degree of irregular astigmatism.
While severe uncorrected astigmatism can make many daily tasks arduous and potentially dangerous, even mild amounts can reduce visual acuity and comfort. Fortunately, the symptoms can usually be corrected with prescription glasses, contact lenses, or refractive surgery to provide clear undistorted sight similar to normal vision without astigmatism.
