How can you need glasses for both far vision and close up?

[onerousdeporte]

Went to the optician (specsavers) and had a special eye test.  But not sure that the did ocular pressure, as there was no thing bouncing off my eyeball.

Bye the bye, was told I need glasses for driving at night, due to being short sighted slightly.  Also glasses for reading close up.  How does that work

[Séamas M.]

It's quite common. Lots of people need reading glasses as they get older and if they were short sighted in their early life (like me!) that condition remains, hence needing multiple sets of glasses or varifocals or bifocals.

[toontra]

My guess would be - age!  Eyes deteriorate along with other body parts.  I use multi-focal GRP lenses which (mostly) correct for both.

[onerousdeporte]

My guess would be - age!  Eyes deteriorate along with other body parts.  I use multi-focal GRP lenses which (mostly) correct for both.

Not accepting that....

[HTFB]

It hits in your mid-to-late forties. I have varifocals, and distance-only sunglasses, and mid-distance glasses for the computer, and I really could do with a pair of sewing glasses for close work. I feel increasingly like Professor Branestawm.

[onerousdeporte]

It hits in your mid-to-late forties. I have varifocals, and distance-only sunglasses, and mid-distance glasses for the computer, and I really could do with a pair of sewing glasses for close work. I feel increasingly like Professor Branestawm.

Aren't new retinas possible to make this all wonderful...

[sojournermike]

Yep - I’ve become long and short sighted…

[Polar Bear]

I read somewhere (or did my lovely optometrist tell me ... 🤔 ) that typically by the time that you are 60 you need four times as much light to get the same clarity of image as you did when you were 20.

Now, I don't know the science behind this but our eyes do deteriorate significantly with time with lenses becoming less flexible, eyeballs changing shape and sensitivity reducing.   To get the science we need an expert ...

[ian]

It's really all part of the Big Optician conspiracy to make you buy expensive glasses. You've looked up and seen the chemtrails, right? There's your mistake right there.

But yes, your lens loses flexibility and elasticity with age (as does skin and other connective tissues) so it can't be squished and pulled by the muscles to give you the same range of focus. No one entirely understands the precise why but there are theories, but it is normal aging.

[Kim]

IANA optiquack, but AIUI you can be short-sighted or long-sighted (one or the other, not both) due to insufficiently spherical eyeballs.  See also astigmatism.  This usually happens early in life.

On top of that, you can lose focusing range as you age (not sure if this is a neuromuscular problem or due to the lens becoming less flexible).

The conspiracy is of course a joint effort between the manufacturers of display devices, cramming in ever more pixels that you can't resolve, and the lighting people making their products slightly dimmer every year...

[rogerzilla]

I need glasses for everything* because I am properly longsighted, as opposed to presbyopic (limited focus).  Which, being 54, I am too.  So +a bit for distance and +a lot for reading.

*I can do anything not involving reading without them, tbh; my prescription is quite weak

[hellymedic]

There is a difference of around 4 dioptres between the lenses needed for close up focussing like reading, and for infinite distance.

When a person is young, the lenses in their eyes are elastic and  eye muscles can reshape the lens for sharp focus.

The lens stiffens progressively after about the age of around forty, and stronger lenses are needed for reading, even if distance vision is fine.

If distance correction was needed that will remain, whilst reading correction will still be needed.

[Kim]

I seem to be in an annoying state where my distance prescription hasn't changed for years, but I need that correction for increasingly close objects (which appears to now include the far end of my monitor).  No problem with paper-reading distances, other than wanting more and more light for fiddly electronics work or similar.

[Diver300]

Bye the bye, was told I need glasses for driving at night, due to being short sighted slightly.  Also glasses for reading close up.  How does that work

The lenses get stiffer with age, so they can't be stretched as much as they used to, so the range of focus is reduced.

[slowfen]

The lens does not only stiffen, but also loses clarity, preventing light getting to the retina (cf think clear plastic yellowing with age)

[TheLurker]

Shouldn't this really be in the, "You know you're middle aged when..." thread? 

[Lightning Phil]

Went to the optician (specsavers) and had a special eye test.  But not sure that the did ocular pressure, as there was no thing bouncing off my eyeball.

Bye the bye, was told I need glasses for driving at night, due to being short sighted slightly.  Also glasses for reading close up.  How does that work

Welcome to middle age

[Rod Marton]

I read somewhere (or did my lovely optometrist tell me ... 🤔 ) that typically by the time that you are 60 you need four times as much light to get the same clarity of image as you did when you were 20.

Now, I don't know the science behind this but our eyes do deteriorate significantly with time with lenses becoming less flexible, eyeballs changing shape and sensitivity reducing.   To get the science we need an expert ...

Actually the transmittance of the eye doesn't reduce quite that much with age, but it does reduce, particularly at the blue end of the spectrum. Transmittance might reduce by about half for blue light, but hardly at all for red light. There will also be increased scatter, so you will get a bit of image blurring, but this is broadly independent of wavelength.

The eyeball doesn't change shape much after adolescence, the problem with age is that the range of accommodation reduces. I've heard this explained as both due to the muscles weakening and the lens getting stiffer: really it's probably a bit of both. What definitely happens is that the lens gets thicker with age, it's one of the few parts of the body where the cells aren't replaced so you just get new layers added on the outside. Which is also why you get increased absorption with age: all the metabolic waste products stay in the lens and these absorb light.

[HTFB]

I read somewhere (or did my lovely optometrist tell me ... 🤔 ) that typically by the time that you are 60 you need four times as much light to get the same clarity of image as you did when you were 20.

Now, I don't know the science behind this but our eyes do deteriorate significantly with time with lenses becoming less flexible, eyeballs changing shape and sensitivity reducing.   To get the science we need an expert ...

Pinhole camera effect as well as reduced transmission and a less efficient retina. In bright light a smaller pupil makes up for your inaccurately focused lens.

[onerousdeporte]

It's really all part of the Big Optician conspiracy to make you buy expensive glasses. You've looked up and seen the chemtrails, right? There's your mistake right there.

Ah big optician, got it.

IANA optiquack, but AIUI you can be short-sighted or long-sighted (one or the other, not both) due to insufficiently spherical eyeballs.  See also astigmatism.  This usually happens early in life.

That is what got me thinking, as I have a damaged/deformed eye.  Or have been told that in the past yet wasn't this time.

The conspiracy is of course a joint effort between the manufacturers of display devices, cramming in ever more pixels that you can't resolve, and the lighting people making their products slightly dimmer every year...

So this is big getting to us?

[perpetual dan]

I went to the opticians today. I’m a little less short sighted than I used to be. Not enough to make any practical difference, except to my bank balance. But I absolutely need the reading bit of my prescription too.

[TPMB12]

A few years back one eye got better.  Annoyingly it dropped the value of the nhs voucher I got to about £13 from £28  iirc. One eye -10.25 & the other became -9.75 from the previous -10.25. Still,  I always get free eye tests every 2 years but that missing voucher value really was noticed!   

Seriously, what use is that voucher? No glasses cost that little and with my prescription the lenses would not be useable because of edge distortion. As I found out with work provided safety glasses. It's like no straight lines are possible looking through them. Not good when I'm a quality engineer needing to measure and read engineering drawings! Lucky if I get change put off £300!

Oh and 4 or so years ago the optician said I was close to needing reading glasses. I got the offer of them but was up to me so no! I'm holding that day off as long as possible. Varifocals? Jeez! With my prescription I'd need a mortgage on them! However I accept that it's going to go down that way eventually.

Oh and then the optician says you need blue light filter driving glasses to safely drive at night! Add in my need to get fl41 tint glasses for health reasons. Let's just say I'm the guy who earns the optician her annual bonus!

[onerousdeporte]

Now a blue glasses are intriguing https://www.specsavers.co.uk/glasses/glasses-lenses/do-blue-light-glasses-work

Though got used to wearing yellow glasses while driving as led lights cause me difficulty.

[TPMB12]

Local independent opticians have a piece of equipment to help you choose the best colour filter for various photosensitivity people can have. Apparently you can get a wide range of filters depending on your needs.

I'm interested in fl41 tint. It's originally developed for fluorescent lighting environments but it's especially useful for people who are photosensitive as a trigger for their migraines. Also good for other photosensitive conditions. However at £115 for clip ons let alone prescription lenses it's gong to be a delayed purchase.

[mrcharly-YHT]

The blue filter lenses I uses are tinged slightly yellow.

They make a huge difference for computer use, and preventing 'artifacts' when driving at night.

Won't have glasses without them now.