Old Eyes: An Introduction to Presbyopia

Rooted in Greek, with ‘pres’ meaning ‘old man’ and ‘bios’ meaning sight, the term refers to a gradual change in close-range sight after age 40. However,  presbyopia is not a serious medical condition, but merely a phase that most people go through as they age; even in the absence of a prior ocular condition.

Symptoms

Presbyopia may be the culprit if you are over 40 and have:

• Eye strain.
• Trouble reading the fine print.
• Difficulty seeing closely placed objects.
• Visual fatigue after performing visual tasks.

When to see a doctor

Go for a check up if blurry close-up vision is keeping you from reading, doing close-up work, or enjoying other normal activities. He or she can determine whether you have presbyopia and advise you of your options.

Seek urgent medical care if you:

• Have a sudden loss of vision in one eye with or without eye pain
• See flashes of light, black spots or halos around lights
• Have double vision
• Experience sudden hazy or blurred vision

Risk factors

Certain factors can make you more likely to develop presbyopia, including:

• Age

Age is the greatest risk factor for presbyopia. Almost everyone experiences some degree of presbyopia after age 40.

• Other medical conditions

Being farsighted or having certain diseases — such as diabetes, multiple sclerosis or cardiovascular diseases — can increase your risk of premature presbyopia, which is presbyopia in people younger than 40.

• Drugs

Certain drugs are associated with premature presbyopic symptoms, including antidepressants, antihistamines and diuretics.

How It Happens

The clear, flexible lens behind the iris helps focus on both close-range and far-range objects by changing its shape accordingly. However, these lenses gradually thicken and begin losing flexibility with age, the muscle fibers surrounding the eyes harden, making a change in shape and focus difficult. These factors collectively contribute towards the gradual reduction in close-range vision.

Moreover, a previous diagnosis of farsightedness, diabetes, multiple sclerosis, cardiovascular diseases, or taking prescription-grade antidepressants, diuretics (for bladder issues), or anti-histamines (anti-allergy) may cause premature presbyopia in certain individuals under 40.

Treatment

As it is a normal part of aging, presbyopia cannot be stopped or reversed. However, special prescription eyeglasses, contact lenses, and surgery in extreme cases can help correct the condition:

1- Glasses

Prescription eye wear works by refracting (bending) light rays before entering the eyes, with multiple options available depending on the condition’s progression:

• Reading Glasses: are the perfect solution for presbyopic individuals who only have trouble with fine print and close-range reading and have no prior eye issue like astigmatism or farsightedness. Users will only wear these glasses when reading.
• Bifocal Lens: Divided into two portions, the top part of the lens refracts light for clear distant viewing, while the bottom part refracts light for close-range correction.
• Trifocal Lens: Correct both presbyopia and myopia (near sightedness) along with additional mid-range vision correction.
• Progressive Lens: Refraction gradually changes from top to bottom instead of distinct sections like bifocals, thus allowing clear vision at all distances regardless of additional refractive errors.

Note: Regardless of eyeglass choice, users should opt for lenses with anti-reflective coating and photochromic properties (darkening with sunlight exposure) to reduce glare and light sensitivity respectively in order to eliminate distracting and eye-straining reflections.

2- Contact Lens

While an excellent alternative for those who wish to forego eyeglasses, contact lenses may not be a suitable option for individuals with eyelid, tear duct, or eye surface related conditions.

• Monovision Contact: One lens corrects for farsightedness while the other corrects nearsightedness in people with multiple refractive issues. However, these lenses may reduce depth, distance, and speed perception in some individuals.
• Multifocal Contact: Several rings in each lens are set at different powers for accurate near and distant vision, wherein the brain selects the right ring for the needed focus. However, these lenses may reduce vision sharpness.

3- Surgery

Although contact lenses and eyeglasses can commonly resolve such vision problems, some individuals may require or opt for surgical correction:

• Corneal Inlay Implantation: A small plastic ring with a central opening is implanted in the cornea of the non-dominant eye to increase focus and reduce the need for reading glasses by allowing in a concentrated amount of light.
• Refractive Lens Exchange (RLE): The affected lens is replaced by an artificial intra ocular lens than can either be multifocal (for multiple refractive errors) or accommodating (for vision clarity at all distances). However, one risks blurring, inflammation, bleeding, and glaucoma by opting for this method.
• Monovision LASIK: Based on the principle of monovision contact lenses, this surgical method entails the use of a laser beam to alter the shape of each lens according to their respective refractive error.
• NearVision CK (Conductive Keratoplasty): Radio frequency waves are used to alter the shape of the cornea in one eye for presbyopia correction.

The strength of presbyopic prescriptions may increase with time due to age-related changes in the human lens, so make sure to get regular eye exams. You can also book an appointment with a top ophthalmologist in Islamabad, Faisalabad and Karachi through oladoc.com, or call our helpline at 042-3890-0939 for assistance to find the RIGHT doctor for your ocular concerns.