We Are Getting Older Every Day: And so Are Our Eyes
Interview with Dr. Alexander Leube, Optometrist and Visual Scientist at the ZEISS Vision Science Lab in Tübingen (Germany)
We are getting older every day – and so are our eyes. So do our eyes really change all the time, i.e. as we turn 30, 40 or 50?
Yes, that’s a fact. Our eyes are subject to normal physiological processes that never stop. In particular, this concerns the ability of our visual system to focus on nearby objects, which worsens as we get older. This is a gradual process that is already present at around the time we turn 30 – and it becomes apparent at 40. That’s when people who already wear glasses start to need lenses that help them see better at close range. At 50, it becomes all too evident that we need to hold our smartphones much further away in order to see clearly. In other words, the eye’s lens is no longer able to make out close-up objects clearly – this is what we call “accommodation” and is normally the time when glasses wearers need to switch to progressive lenses.
Why does this happen?
It’s a normal part of the aging process. The eye’s lens starts to lose its elasticity due to a range of physiological processes. The elasticity results in the eye’s lens becoming more spherical at an early age when looking at objects at close range. Loss of elasticity means an increase in the refractive power is no longer possible; this is also known as presbyopia. Some people say this depends on the ciliary muscle. The solution would be to train them and then you’ll be able to see nearby objects clearly, even as you get older. However, the muscles function is preserved with age and it’s actually due to the stiffening of the eye’s lens.
Does that mean we’ll all eventually need to wear glasses?
It’s not that we’ll all become short- or far-sighted at some stage, but we will all suffer from presbyopia in later life. Optically speaking, this isn’t a typical refractive error but simply a normal physiological change. We will all eventually have to wear a pair of reading glasses, no matter how old we are when we do so – though progressive lenses are always an option, too.
Do our eyes keep changing as we get older?
Many things change for example the composition of our tear film. A major change affects the size of the pupil, which determines how much light enters the eye. If it’s dark, the pupil will normally dilate in order to make the most of the little available light. As we grow older, the pupil becomes increasingly smaller. This is a compensation process as it allows the light to enter the eye more bundled. This phenomenon continues to compensate for the worsening of the eye’s lens; we talk about an increased depth of field. As a result, one does not realize that the lens starts to weaken. But this equalization does not go on indefinitely. However, this normal physiological change in pupil size can now be taken into account in modern lens design.
What happens to our eyes as we get even older?
Presbyopia can easily be corrected with progressive lenses. The aging of the society leads to further age-dependent eye conditions involving the retina or the eye’s lens. Cataract is a very common eye disease whereby the lens becomes increasingly cloudy, thus allowing less light to enter the eye. If untreated, this can cause blindness. Fortunately, a simple surgery can be performed to resolve it. Inserting a standard intraocular lens into the eye is enough to restore clear vision.
Thank you very much for talking to us.
ZEISS Vision Care