It is normal and important to learn more about it!
What it is about
Presbyopia is a condition when the distance of a near point increases when a person ages (Goldstein, 2014). The lens hardens with age and ciliary muscles weaken (Goldstein, 2014). This makes it difficult for vision at close range when a person gets older. This can be helped with reading glasses or holding things further away. At the age of 20, the near point is about 10 to 14 cms but by age 60, it goes up to 100 cms (Goldstein, 2014).
Effects can be related to both age limitation of the eye and neural processing delay (Lockhart & Shi, 2010). As we age, different things in our bodies begin to change. It is completely normal but can be difficult for many. The accommodative system has a lot to do with this. It is controlled by crystalline lens which changes its curvature and its shape in order to create a proper optical power to your eyes in order to give you a clear image at different distances (Lockhart & Shi, 2010). The accommodative system changes with age like many things which causes the degeneration. With the lens hardening, the tension of fibers called Zonulars decline, which causes the activity of the ciliary muscle to decrease (Lockhart & Shi, 2010).
Treatment used to be used through magnifying glasses and reading glasses. There are also bifocal contact lenses which can help but are not ideal (Schachar, 2014). There is also monovision and lasik surgery for those with or without a hydrogel lens or a corneal pinhole which has success (Schachar, 2014).
Exceeding your Expectations. (2016). Retrieved from Thomas Vision: http://www.thomasvisionclinic.com/eye-health/just-for-presbyopes
Goldstein, E. B. (2014). Sensation and Perception (9th Edition). Belmont: Wadsworth.
Lockhart, T. E., & Shi, W. (2010). Effects of Age on Dynamic Accommodation. Ergonomics, 892–903.
PRODUCTS, S. O. (2016). SEIKO OPTICAL PRODUCTS. Retrieved from Presbyopia: http://seikoeyewear.com/eye-information/about-the-eyes/presbyopia
Schachar, R. (2014, September 23). Presbyopia - Cause and Treatment. Retrieved from Medscape: http://emedicine.medscape.com/article/1219573-overview#a7
Here you see what the eye normally sees when looking at objects nearby. This is when the Cystaline lens is still fine. You also see what it looks like when the lens is hardened and before it is.
As many get older, they have to read things this way in order to see properly. The lens is getting hard and it is easier for them to see things better.
Young Age Versus Old Age
This is an example how the light goes through. When it hit the lens as you get older, it is more difficult to see.