Loss of Accommodation: Why Your Eyes Cannot Focus Up Close

What accommodation means

Accommodation is how the eye changes focus. Inside the eye, the ciliary muscle surrounds the flexible lens. To focus on something near, the muscle contracts, the lens rounds up and becomes more powerful. Accommodation works together with the pupils getting smaller and the eyes turning inward (convergence), a combination called the near reflex.

Loss of accommodation means the lens cannot change shape enough, the ciliary muscle is weak, or the nerve controlling it is affected.

Symptoms

• blurred vision when reading, sewing or using a phone
• holding reading material farther away ("my arms are too short")
• needing brighter light to read
• eye strain, aching eyes and headaches after close work
• slow refocusing when looking from near to far
• small print becoming hard to read, especially in the evening

Causes of loss of accommodation

Presbyopia (age-related)

Presbyopia affects everyone eventually. From childhood, the lens gradually hardens. Most people notice difficulty with near tasks in their early to mid-40s, and it progresses until about age 60, by which time little accommodation remains. People who are farsighted (hyperopia) notice it earlier. Nearsighted people may find they can read by taking off their glasses.

Accommodative insufficiency in younger people

Some children, teens and young adults have weaker focusing than expected for their age. They get blurred near vision, tired eyes and headaches with reading, and may avoid homework. It can follow a viral illness or concussion and often occurs with convergence insufficiency. Vision therapy or reading glasses help.

Medicines

Drugs with anticholinergic effects relax the ciliary muscle: some antihistamines, tricyclic antidepressants, antipsychotics, bladder medicines (such as oxybutynin), scopolamine patches for motion sickness, and dilating eye drops used during eye exams. Effects from eye drops wear off within hours. Scopolamine on the fingers rubbed into one eye can cause one-sided blurring and a large pupil.

Eye conditions and injury

• blunt trauma damaging the ciliary muscle or lens
• early cataract and lens surgery (a standard artificial lens does not accommodate)
• inflammation inside the eye (uveitis)
• Adie's tonic pupil: a large pupil in one eye that reacts slowly, with poor near focus, often in women aged 20 to 50 after a viral illness

Whole-body and nerve causes

• diabetes: fluctuating blood sugar changes lens shape, and diabetes is linked to earlier presbyopia
• third cranial nerve palsy, from diabetes, high blood pressure or, urgently, an aneurysm
• botulism, diphtheria and some other toxins
• head injury and concussion
• myasthenia gravis, multiple sclerosis and Parkinson's disease (sometimes)

How it is diagnosed

An optometrist or ophthalmologist will check vision at distance and near, measure your glasses prescription, and test how close you can focus clearly (the near point of accommodation). They will examine your pupils, eye movements, eyelids and the inside of the eye. If only one eye is affected, onset is sudden, or the pupil or eyelid is abnormal, they will look for a nerve or medicine cause, and may arrange urgent brain imaging.

Treatment

• Reading glasses for near tasks. Over-the-counter readers suit many people with similar prescriptions in both eyes and no astigmatism.
• Bifocals, trifocals or progressive lenses combine distance and near correction.
• Computer glasses for intermediate distances.
• Multifocal or monovision contact lenses.
• Prescription eye drops (such as low-dose pilocarpine) make the pupil smaller to increase depth of focus for some hours. They can cause headache and dim vision in low light and are not suitable for everyone.
• Surgery: lens replacement with multifocal implants, or laser monovision, for some people.
• Vision therapy for accommodative and convergence insufficiency in younger people.
• Treating the cause: stopping or changing a medicine, controlling blood sugar, or managing a nerve problem.

Good lighting, larger font sizes and regular breaks from close work reduce strain.

Frequently asked questions

What is loss of accommodation?

It is a reduced ability of the eye to change focus to see near objects clearly. The lens or the muscle that changes its shape does not work as well. The most common cause is presbyopia, which affects nearly everyone from their 40s.

Is loss of accommodation the same as presbyopia?

Presbyopia is the commonest type, caused by the lens hardening with age. Loss of accommodation can also happen at younger ages from medicines, eye injury, diabetes, nerve problems or accommodative insufficiency.

Can loss of accommodation be reversed?

Presbyopia cannot be reversed, but it is easily corrected with glasses, contact lenses, drops or surgery. Loss caused by medicines usually reverses when the drug is stopped. Some nerve and post-concussion causes improve over weeks to months.

Why can't my child focus on close objects?

Children can have accommodative insufficiency, uncorrected farsightedness or convergence problems, causing blurred near vision, headaches and reading avoidance. A full eye exam, not just a school vision screen, is needed to find these.