Presbyopia
What is presbyopia?
Presbyopia is a common age-related condition in which the eye's lens loses its flexibility, and your eyes gradually lose the ability to focus on objects up close. Presbyopia typically becomes more noticeable shortly after the age of 40 and progresses until around the age of 65.
How does presbyopia occur?
Presbyopia occurs due to age-related changes in the eye's lens and surrounding muscles. The lens that sits behind your iris gradually becomes less flexible and rigid, making it difficult to change its shape to focus on close objects. Hence, it is harder to read, thread a needle, or do other close-up tasks. Additionally, the muscles that control the shape of the lens also weaken due to the ageing process, further contributing to the difficulty in focusing up close.
Symptoms of Presbyopia
- 1. Eye strain (when eyes feel tired or sore)
Patients with presbyopia may experience eye strain, as their eyes have to work harder to focus on objects near them. This increased effort can lead to symptoms like eye strain and possibly headaches, mainly when performing prolonged close-up tasks.
- 2. Difficulty seeing things up close
Patients with presbyopia have difficulty focusing on close objects. As the lens loses its flexibility with age, it is hard to adjust focus, especially for near-vision tasks like reading or using a computer. People who are short-sighted and experiencing presbyopia would find themselves needing to lift up or remove their glasses to read more easily.
- 3. Moving objects (e.g. phones) away to see them clearer
Moving objects farther away reduces the focusing demand on their eyes, making it easier for them to see clearly, a common coping mechanism for patients with presbyopia.
How to manage presbyopia?
- 1. Progressive lenses
Progressive lenses have a seamless increase in magnification from the top to the bottom of the lenses, helping you see clearly at all distances with just one pair of glasses. The top portion of the lens is used to see distant objects, the middle portion is used to see intermediate objects, and the bottom is used to see things up close.
The lenses' prescription changes gradually across the lens surface, providing a gentle and smooth transition. The transition between close-up and distant viewing avoids an "image jump," in which objects abruptly change in clarity and apparent position as your eyes move across the prescriptions in the lenses. However, new patients wearing progressive lenses will have to learn to look out for the correct position of the lenses, as there are no visible lines to guide them.
- 2. Reading glasses
Reading glasses are glasses with lenses that have a magnifying power specific for near-vision tasks. They work by providing additional magnification to compensate for the eye's reduced focusing ability. They are available over-the-counter in various powers ranging from +1.00 to +3.00 dioptres.
- 3. Multifocal contact lenses
Multifocal contact lenses are contact lenses that work similarly to progressive lenses. They provide multiple prescriptions in one lens: one for very close objects, distant objects and one for intermediate objects. This allows wearers to see clearly at different distances without removing or switching between glasses. It also comes in soft and hard (rigid gas permeable) contact lenses. In short, multifocal lenses provide the same advantages as progressive lenses.
References:
- https://www.aao.org/eye-health/diseases/what-is-presbyopia
- https://www.aao.org/eye-health/diseases/hyperopia-farsightedness
- https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/presbyopia
- https://www.aao.org/eye-health/glasses-contacts/pros-cons-progressive-lenses-computer-glasses
- https://coopervision.com.sg/about-contacts/multifocal-contact-lenses