When we are young, the lens in our eye is soft and flexible, and can change shape easily to bend the light rays and focus them onto the retina. This allows you to focus on close-up objects as well as those that are far away.
As we age, the lens loses its elasticity and becomes stiff. As a result it cannot change its shape easily and is unable to bend the light properly to focus it on your retina. Consequently you cannot focus on close objects clearly, making it harder to read, thread a needle, or do other close-up tasks.
This condition is known as presbyopia. A normal part of aging, presbyopia is a refractive error that affects most adults over the age of 40, when the eyes gradually lose the ability to see things clearly up close.
Common symptoms of presbyopia include:
- Inability to read or perform near tasks comfortably. Eyestrain or headaches after reading.
- Difficulty in reading small print.
- Need for brighter lighting when reading or doing near work.
- Holding the reading material at an arm’s length to focus properly on it.
- Overall problems seeing and focusing on objects that are close to you.
- More sensitivity to light and glare
Presbyopia Diagnosis
Since presbyopia results due to age-related changes in the eye in people over the age of 40 years, all adults should have a baseline eye examination at age 40. Annual eye screenings after age 40 can identify early signs of eye disease and vision changes that can sometimes arise without any symptoms around this age. People with existing hypermetropia
(far-sightedness) or those with an increased pressure within the eye, including glaucoma patients, may be affected earlier. Near vision testing using different charts such as the Snellen’s near vision chart or the Jaeger’s chart can be used to diagnose this condition.
Presbyopia Treatment
There is no way to stop, slow down or reverse the natural process of age-related changes that leads to presbyopia. However, presbyopia can be corrected with eyeglasses, contact lenses or laser surgery. If presbyopia is not corrected, you may experience headaches and eye strain.
Optical correction
Eye glasses with bifocal or progressive lenses would be the usual and most common resolution to these issues. This can correct both distant and near vision simultaneously. Progressive spectacles also take care of intermediate vision and help those working on computer screens. Certain people however prefer reading spectacles alone to continue near work and a separate pair for distant vision. If people do not want to wear glasses due to aesthetic and cosmetic reasons or for functional reasons, then they can opt for contact lenses. People who do not want to use either glasses or contact lenses can opt for refractive surgery.
Presbyopic Lasik
This is an advanced type of laser surgery which modifies the shape of the cornea, creating different zones of power to see at various distances. The laser creates zones of power for far, near and intermediate vision. Your brain will adapt to select the zone needed to obtain clearest vision depending on where the object is located. This aims to give you clear vision and make you glass free for distance as well as near vision. It may also be dependent or independent of the lighting in the room and the size of the pupil.
Other surgical options for correction of presbyopia include:
- Lens based procedures such as refractive lens exchange, where the natural lens is replaced by a multifocal intraocular lens (IOL) or an accommodating IOL to restore near vision.
- Surgical implantation of a corneal inlay, which is a tiny optical device (similar to a contact lens) that is inserted into the cornea to improve reading vision.
- Conductive keratoplasty (CK), where radio frequency waves are used to alter the curvature of the cornea to improve near vision.
Inability to read comfortably and needing to keep the material at an increased distance, are the main symptoms of presbyopia. Normally it starts after 40 years of age. Near vision testing using different charts like Snellen’s near vision chart can pick up this. Eye glasses with bifocal or progressive lenses would be the usual and most common resolution to these issues. If people do not prefer to wear glasses they have the option of contact lenses. Refractive surgery for presbyopia is also available for people who do not wish for either glasses or contact lenses.
