Presbyopia — Greek for “aging eye” or “old eye” — is an age-related, progressive loss of accommodative amplitude of the eye lens. The eye condition results in inability to focus on close-up objects.
Progression of aging eye begins soon after ocular growth is complete. It usually becomes noticeable in the early to mid-forties. The complete loss of accommodation usually peaks by age 50 years. As other natural aging process, it can’t be prevented.
Possible Causes of Aging Eye
There are several theories of the causes of old eye. But most researchers agree that hardening of the crystalline lens and a loss of ciliary muscle elasticity as the main causes.
If you have normal eyes, your eye lens is in a relaxed position when you see a distance object. When you want to see a close-up object clearly, the crystalline lens must change shape to increase its power. The process of increasing power to see near distance clearly is called accommodation. Below is a description of the accommodation process:
- The eye lens is surrounded by a focusing muscle, called the ciliary muscle. The lens is attached to the ciliary muscle by tiny fibers called zonules.
- When you see a close-up object, the ciliary muscle contracts and the zonules increase tension on the lens. This makes the lens change shape to a higher curvature to get a higher focusing power.
- As you get older, the crystalline lens gradually loses its accommodation ability. The hardening lens can no longer increase its power to see a near object clearly. The insufficient accommodation ability usually happens after 40 years of age.
There is no satisfactory explanation whether the loss of accommodation is caused by the hardening lens, the reduced ciliary muscle movement, or both. It’s still not clear also if one is a consequence of the other. The agreed one is that the age-related changes create a unique, eye system failure called aging eye.
Signs and Symptoms of Aging Eye
A common first sign of aging eye is inability to read fine print, such as a label of medicine bottle, comfortably. Another sign of aging eye is easily fatigue while reading a book or looking at a computer screen.
The following list is common symptoms of presbyopia:
- Experiencing Blurred vision and less contrast at a normal reading distance
- Easily feel eyestrain and headache when doing close work
- Requiring for more direct light for reading
How to Correct Aging Eye?
Presbyopic eye acts like a “fixed-focus” camera, which means that it’ll see well only at a particular distance. If your distance vision is normal, for example, all you need is over-the-counter reading glasses.
If you correct near vision you’ll see clearly up-close, but you can’t see distance object clearly with the correction and vice versa. Correcting reading vision is always at the expense of distance vision and vice versa.
“Can I have a simultaneous near and distance vision correction?” Only if you can restore accommodation… Unfortunately, both optical and surgical options do not restore dynamic accommodation. In other word, there are no universally accepted cures currently available for old eye.
Optical and Refractive Surgery Options
The following are optical options for presbyopia treatment: reading glasses, bifocals or progressive eyeglasses, bifocal contact lenses, and monovision contacts.
If you’re considering a refractive surgery, there are several options that are approved by the FDA, such as LASIK monovision and monovision with CK (conductive keratoplasty). Or, there are other surgeries that aren’t approved by the FDA, such as ACS (anterior ciliary sclerotomy), Scleral Expansion Bands, and SPR (surgical presbyopia reversal).