Vision problems: questions, page 2

It cannot be prevented with certainty. In children, time outdoors is consistently associated with slower development of short sightedness, and treatments exist that aim to slow its progression. In adults, there is nothing established that stops a refractive error from developing.

This question on its own page

The distinction worth keeping is between slowing and preventing. Slowing progression in a child is a recognised clinical aim with recognised methods; preventing an adult from becoming short sighted is not something any treatment here claims to do.

• Slowing short sightedness in children
• Myopia explained

Sources National Eye Institute, National Institutes of Health (US) , American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

The eye’s length and the focusing power of its cornea are not reversed by treatment: glasses, lenses and surgery compensate for them. In children the prescription usually increases as the eye grows, and in some adults it continues to change slowly.

This question on its own page

• Why stability matters before surgery

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

High short sightedness generally means a prescription beyond the moderate range, and there is no single boundary that every clinician uses. What matters practically is that higher prescriptions ask more of the cornea, which is why they are planned from thickness and shape measurements rather than from the prescription alone.

This question on its own page

Higher short sightedness is also associated with a greater chance of retinal problems later in life, which is a reason for regular dilated examinations rather than a reason for alarm. That monitoring question is separate from whether laser surgery is suitable.

• Options for high prescriptions
• Eligibility guide

Request a consultation

Sources StatPearls, NCBI Bookshelf , American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Higher short sightedness is associated with a greater chance of retinal detachment, retinal changes and, later, glaucoma and cataract. The association is with the length of the eye rather than with wearing glasses, and it is a reason for regular dilated examinations.

This question on its own page

Laser vision correction changes the cornea and not the length of the eye, so it does not remove this. Whatever your vision is like after surgery, the retina still needs the same monitoring as before.

• Retina and retinal screening
• Which symptoms need urgent care

Sources American Academy of Ophthalmology , National Eye Institute, National Institutes of Health (US)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

There is a substantial inherited component, and the chances are higher when one or both parents are short sighted. Environment also matters, with sustained near work and less time outdoors associated with earlier onset in children.

This question on its own page

• Short sightedness in children

Sources National Eye Institute, National Institutes of Health (US)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

No. Long sightedness (hyperopia) is a focusing error you are born with, where the eye’s optical power is too weak for its length. Presbyopia is the age-related stiffening of the lens that affects near focus later in life. Both blur close vision, and they are different problems with different corrections.

This question on its own page

The reason the two get merged is that they feel similar: reading gets harder, and holding things further away helps. The reason it matters is that they respond to different treatments. Hyperopia is a refractive error a laser or lens can correct; presbyopia is a change in the lens that no laser can reverse.

• Hyperopia explained
• Presbyopia explained

Sources American Academy of Ophthalmology , StatPearls, NCBI Bookshelf

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Yes, and mild long sightedness is common in young children, whose eyes focus well enough to compensate for it. Most grow out of it as the eye lengthens. A young child with a high prescription may need glasses, because the effort of compensating can affect how the eyes work together.

This question on its own page

A child who compensates well will not complain, which is why the finding usually comes from a routine examination rather than from a parent noticing something. That is one of the arguments for testing children before school rather than waiting for a symptom.

• Children’s eye health
• When should children have their eyes tested?

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

The prescription itself usually changes little. What changes is your ability to compensate for it: the lens stiffens with age, so the same amount of long sightedness becomes harder to hide, and people often notice symptoms in their thirties or forties that were always there.

This question on its own page

This is also why someone can be told they are long sighted at 42 after a lifetime of seeing well. The finding is not new; the compensation is.

• Eligibility guide

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

It can be corrected rather than cured. Glasses, contact lenses and refractive surgery all change where light focuses in the eye; the shape of the eye itself is unchanged, and it can keep changing with age. Long sightedness can also be corrected during cataract surgery, when the natural lens is replaced anyway.

This question on its own page

• Compare every option
• Cataract surgery and lens choice

Sources StatPearls, NCBI Bookshelf , National Institute for Health and Care Excellence (UK)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

There is a strong inherited tendency, and the way the eye grows matters as much as eye optics: a shorter-than-average eye is long sighted. A family history does not predict an individual’s prescription, but it is a reason to have children tested rather than to wait for symptoms.

This question on its own page

• Children’s eye health

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

By refraction: a test that finds the lens power that gives you the clearest vision, expressed as a prescription with a plus sign for long sightedness. In younger patients the measurement is usually repeated after drops that relax the focusing muscle, because otherwise the eye hides part of the prescription.

This question on its own page

The drops matter more in this prescription than in short sightedness. A long sighted eye compensates by focusing harder, and a refraction taken without relaxing that effort can understate the true figure, which is the figure surgery would be planned from.

• What happens during a comprehensive eye examination
• The eye examination, explained

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

It can, because the eye is doing continuous work to compensate. The usual pattern is discomfort after sustained near tasks, such as reading or screen work, rather than a headache on waking. Blur is not always present, which is what makes this easy to attribute to something else.

This question on its own page

• Eye strain and screens

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Surface treatments and flap procedures can both correct hyperopia, and lenticule extraction is not a routine hyperopia treatment on the platforms in general use. The choice depends on your measurement and on what is cleared for use where you are treated.

This question on its own page

Long sightedness is one of the reasons a clinic’s assessment matters more than its advertising. The correction reshapes the cornea to make it steeper, which places different demands on your tissue than the more common myopia treatment.

• Which prescriptions are treatable
• PRK and surface treatments

Request a consultation

Sources StatPearls, NCBI Bookshelf , National Institute for Health and Care Excellence (UK)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Regular astigmatism is an even curvature difference that glasses can correct. Irregular astigmatism is an unevenness that ordinary glasses cannot fully correct, and it is associated with conditions that change the corneal surface, such as keratoconus or scarring.

This question on its own page

The distinction is clinical rather than academic: irregular astigmatism is one of the findings that changes what is possible, and specialised lenses or a different treatment plan may be the answer rather than laser surgery.

• Keratoconus and corneal shape
• Corneal topography explained

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

It can change slowly, and a small amount of against-the-rule astigmatism is common as people get older. A rapid change in one eye, or a new difference between the two eyes, is worth examining rather than watching.

This question on its own page

• Astigmatism explained

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Uncorrected astigmatism can cause eye strain and headaches, particularly after sustained reading or screen work, because the eye works harder to find a clear image. The symptom is not specific to astigmatism, so an examination is what distinguishes it from an uncorrected prescription or dry eye.

This question on its own page

• Eye strain and screens
• Astigmatism explained

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Yes, and both do it well for regular astigmatism. Glasses need a cylinder value in the prescription; contact lenses need a toric design, which is a lens with a specific orientation that has to stay in position on the eye to work.

This question on its own page

Toric lenses rotating slightly on the eye is a common reason someone reports their contact lens vision is good but fluctuates. It is worth mentioning to whoever fits lenses for you rather than putting up with it.

• Contact lenses explained
• Glasses against contact lenses

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

It usually begins to be noticeable around the early forties and continues to change, slowly, for decades. The timing varies considerably between people, and it is affected by your existing prescription: short sighted people often notice it differently from those who have never worn glasses.

This question on its own page

The reason there is no single age is that presbyopia measures the flexibility of the lens, and that changes gradually rather than on a birthday. What most people notice first is not blur but a need for more light, or holding print further away than they used to.

• Presbyopia explained

Sources American Academy of Ophthalmology , National Eye Institute, National Institutes of Health (US)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

The lens inside the eye becomes less able to change shape, so it cannot increase its focusing power for near objects. The muscle that changes it still works; the lens itself becomes thicker and stiffer with age.

This question on its own page

That distinction explains the treatment options. Because the problem is in the lens rather than in the cornea, laser surgery on the cornea cannot restore the lens’s flexibility: the available approaches work by giving you a compromise instead, such as focusing one eye for distance and the other for near.

• Reading vision options

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

No. The change in the lens is not reversible by laser treatment, drops or exercise. What can be done is to compensate for it: reading glasses, varifocals, contact lenses designed for it, monovision, or lens replacement that substitutes an implant for the stiffened lens.

This question on its own page

• Presbyopia options compared
• Refractive lens exchange

Sources American Academy of Ophthalmology , National Institute for Health and Care Excellence (UK)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

They are intraocular lenses designed to give useful vision at more than one distance, used when the natural lens is replaced: during cataract surgery, or as a refractive lens exchange in an eye without cataract. The categories are multifocal, extended depth of focus and accommodating designs.

This question on its own page

They are a real option and not a free one. Every design that adds near vision takes something from distance or from the quality of night vision, and the trade-offs differ between designs. This is a decision worth making alongside the surgeon planning your measurements rather than from a brochure.

• Cataract surgery explained
• Lens implants compared

Request a consultation

Sources National Institute for Health and Care Excellence (UK) , American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Yes, monovision can be created with laser vision correction: one eye is corrected for distance and the other is left or corrected for near. It is a deliberate compromise, and the usual advice is to try it with contact lenses first so you find out whether your brain tolerates it before anything permanent is done.

This question on its own page

• Monovision explained
• Eligibility guide

Request a consultation

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

It is possible, and it is a conversation rather than a yes-or-no. Correction can be planned so that your distance vision improves without making your reading worse, or deliberately set up as monovision. What surgery cannot do is give a 50-year-old the reading vision they had at 25.

This question on its own page

The risk worth naming is the mismatch between expectation and arithmetic. Someone who is mildly short sighted and takes their glasses off to read may find that perfect distance vision removes the reading ability they had been relying on. A good assessment asks what you do without your glasses before answering.

• Eligibility after 40
• Age and laser surgery

Request a consultation

Sources American Academy of Ophthalmology , StatPearls, NCBI Bookshelf

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Blur in one eye suggests something specific to that eye, such as a refractive difference, a surface problem, or an issue with the lens, retina or optic nerve on that side. It is worth an examination rather than a wait.

This question on its own page

One useful habit is to test your eyes separately from time to time, because blur that is limited to one eye is easy to miss when both eyes are open.

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

A sudden change in vision needs urgent assessment rather than an appointment in a few weeks. It can be caused by something on the retina, a vascular event or an acute problem in the eye, and the timing matters for treatment.

This question on its own page

Which symptoms need urgent care

Sources American Academy of Ophthalmology , National Eye Institute, National Institutes of Health (US)

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Eye strain usually comes from sustained effort at a close task, often with an uncorrected or changed prescription, an unstable tear film, or prolonged focus without breaks. It is uncomfortable rather than damaging.

This question on its own page

The common pattern is that the eyes feel heavy and the vision goes soft after long screen or reading sessions, and it improves with rest. Persistent strain despite breaks is worth an eye examination, because the cause is sometimes a prescription that no longer fits.

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Double vision has two broad causes: a problem in one eye, or a failure of the two eyes to align. Both need assessment, and sudden double vision needs it urgently rather than routinely.

This question on its own page

A simple test a clinician may ask you about is whether the double image disappears when you close one eye. It does not diagnose anything, but it points the assessment in a direction.

Which symptoms need urgent care

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Blur on waking is often a tear film problem, because the eye produces less tear overnight and the surface takes a few blinks to stabilise. It can also relate to a contact lens worn overnight, which is a reason to avoid that wherever possible.

This question on its own page

Sources National Eye Institute, National Institutes of Health (US) , American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

A refractive error is a mismatch between the focusing power of the eye and its length, so light does not come to a focus on the retina. Short sightedness, long sightedness and astigmatism are the three common forms, and each is described by a prescription.

This question on its own page

Refractive error is not a disease and does not damage the eye by itself. The reason clinicians still examine the whole eye before treating it is that the same blur can sit on top of a condition that does need treatment.

• Vision correction options
• The eye examination, explained

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.

Short sightedness blurs distance because focus falls in front of the retina, long sightedness blurs near focus for most of the day because it falls behind, and astigmatism blurs in a direction because the cornea is curved unevenly. More than one can be present at once.

This question on its own page

• Myopia explained
• Astigmatism explained

Sources American Academy of Ophthalmology

This information is for educational purposes and does not replace an examination by a qualified eye-care professional.