Can an Emmetropic Eye Suddenly Become Hyperopic? An In-depth Exploration

While it is a relatively uncommon occurrence, an emmetropic (normal vision) eye can suddenly become hyperopic (farsighted). This condition, known as sudden hyperopia, can be concerning and requires a thorough examination by an ophthalmologist to determine the underlying causes. In this article, we delve into the possible causes, symptoms, and recommendations for preventing and addressing sudden hyperopia.

Understanding Sudden Hyperopia

Hyperopia occurs when the eye focuses images behind the retina due to the eye being shorter than normal or the cornea having too little curvature. Although rare, an emmetropic eye can develop hyperopia suddenly, leading to difficulties in focusing on close objects.

Possible Causes of Sudden Hyperopia

Several factors can contribute to the sudden development of hyperopia:

Changes in the Eyes Structure

Any changes in the structural elements of the eye, such as the eye's length or the cornea's curvature, can lead to hyperopia. These changes can be gradual or sudden, depending on the underlying cause.

Cataracts

The development of cataracts can alter the refractive power of the lens, leading to hyperopia. Cataracts are cloudy areas that develop in the lens of the eye, and they can affect visual clarity and focus.

Changes in the Cornea

Conditions that affect the shape of the cornea, such as keratoconus or corneal scarring, can lead to hyperopia. Keratoconus is a condition where the cornea becomes thin and cone-shaped, leading to irregular vision.

Medical Conditions

Several medical conditions can cause sudden changes in vision, including hyperopia:

Diabetes

Fluctuating blood sugar levels can affect the focusing ability of the eye's lens, leading to temporary changes in vision, including hyperopia.

Inflammation

Conditions like uveitis can cause changes in the shape of the lens or the curvature of the cornea, leading to hyperopia.

Age-Related Changes

Presbyopia is a common condition that involves difficulty focusing on close objects due to the aging of the eye's lens. While typically gradual, some people may experience a sudden onset of presbyopia, which can mimic hyperopia.

Medications

Certain medications, such as antihistamines and corticosteroids, can cause changes in vision, including hyperopia.

Trauma or Surgery

Eye injuries or surgical procedures, such as cataract surgery, can alter the refractive status of the eye, leading to hyperopia.

Conclusion

If someone who previously had emmetropic vision suddenly experiences hyperopia, it is essential to seek an eye examination to determine the underlying cause and appropriate treatment. Regular eye check-ups can help identify and address changes in vision early on, preventing more severe complications.

Note: Small amounts of hyperopia can occur and disappear suddenly without significant impact on vision. However, if the hyperopia is larger, such as -0.75 or more, it may require attention. Larger changes can vary over a year between -0.50 to -1.00, but they are not likely to occur suddenly.

Also, it's important to note that the cause of sudden astigmatism may vary. Normal congenital astigmatism does not change much, but secondary astigmatism, such as that caused by a cyst in an eyelid, can change rapidly. It can appear as if the astigmatism has changed by 90 degrees if it is written in form rather than - form or vice versa.