The short answer (prices checked 16 October 2026)
- Cheapest per month of use: Hycosan Fresh, £9.99 for 7.5ml that the listing says keeps for at least six months after opening. That works out at £1.67 a month.
- Best for severe or persistent dryness: Hycosan Extra, £12.98, the number one seller in Amazon UK's Moisturising Eye Drops chart and number 14 across the whole Health and Personal Care department on 16 October 2026. Also six months once opened, so £2.16 a month.
- The cheapest bottle on the shelf is not the cheapest to use. Vizulize at £2.92 states no in-use period at all, so the standard instruction applies and you bin it after 28 days. That is £2.92 a month, more than the £12.98 bottle costs.
- Our listing audit, 16 October 2026: of the first 20 products in Amazon UK's Moisturising Eye Drops chart, only 8 say how long the bottle lasts once you open it, and none of the 20 tells you whether you are buying a licensed medicine or a medical device.
Dry eye arrives with the heating. Hycosan Extra sat at number 14 across the entire Health and Personal Care department on Amazon UK on 16 October 2026, and number one in Moisturising Eye Drops, with another fifteen hyaluronic acid drops stacked up behind it in the same chart. Plenty of people are buying.
What almost nobody is told is how long the bottle they just bought is allowed to stay in the bathroom cabinet. That one number changes the real price by a factor of nine across the six drops below, and it reverses the order of the price tags.
Prices in this table come live from Amazon and can change through the day. Prices quoted in the text were checked by Look Into on 16 October 2026, so the two can differ.
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The table above is Amazon's own live feed, so it can sit slightly off the buy box. On 16 October 2026 the feed had no price at all for the Hyabak and showed £9.88 for the Clinitas against a £9.30 buy box. The prices in the cards and the at-a-glance table are the buy box figures we read that day.
Prices and specs last checked by Look Into on 16 October 2026 · next check 11 December 2026 · how we picked
The number that decides what eye drops cost
Eye drops are sterile. Once you break the seal, the clock starts, and the rule is strict. The Summary of Product Characteristics for Hypromellose Eye Drops BP, a licensed UK medicine holding marketing authorisation PL 15872/0005, puts it plainly: "Discard the bottle 28 days after opening, even if there is solution remaining." Guy's and St Thomas' NHS Foundation Trust gives patients the same instruction for artificial tears generally, telling them to throw the tube or bottle away 28 days after opening. Its dry eye page was last reviewed in January 2026.
Some bottles escape that limit. A preservative-free bottle built around a one-way valve, like the COMOD system Hycosan uses or the ABAK system behind Hyabak, keeps its contents sterile without a preservative and the makers state six months of use after opening. Single-dose vials go the other way: you open one, use it, and throw the rest of that vial away.
So the honest unit for eye drops is cost per month of use. Take the price, divide by the number of months the maker says the bottle is good for, and where the listing says nothing, apply the 28 days the regulator and the NHS both use. Do that and a £2.92 bottle turns out to cost more each month than a £12.98 one, and the dearest bottle in this roundup costs nine times what the cheapest does.
There is a second thing the listings leave out. Some of these products are licensed medicines with a PL number behind them, and some are CE or UKCA marked medical devices. The two sit under completely different rulebooks. Across the 20 listings we read on 16 October 2026, not one stated a PL number or called itself a licensed medicine, and only two said anywhere in their own copy that they were medical devices.
How we picked these
We read the Amazon UK Moisturising Eye Drops best seller chart on 16 October 2026 and opened the product page for each of the top 20. For every one we recorded the buy box price, the stock status, the bottle size and anything the listing said about how long the product lasts once opened, scoped to the product title, the bullet points, the specification tables and the product description. Carousels and related-product copy were excluded, because a page-wide search on an Amazon listing will confirm almost any feature you go looking for.
From that we chose six with genuinely different jobs: one for mild dryness, one for severe, one for the lowest monthly cost, one for the smallest outlay, one for people who react to preservatives, and one for the oily tear film problem. Look Into has not handled these products: every figure comes from the maker, the listing or a named source, read on the date shown. Monthly costs are arithmetic on the price and the stated in-use period, not a measurement.
At a glance
| Drops | Best for | Price on 16 Oct 2026 | Life once opened, as stated on the listing | Cost per month of use |
|---|---|---|---|---|
| Hycosan Fresh 7.5ml | Lowest monthly cost | £9.99 | At least 6 months | £1.67 |
| Hyabak 10ml | Most drops per pound | £11.99 | 6 months | £2.00 |
| Hycosan Extra 7.5ml | Severe or persistent dryness | £12.98 | Up to 6 months | £2.16 |
| Vizulize 10ml | Smallest outlay | £2.92 | Not stated | £2.92 on the 28 day rule |
| Clinitas 30 x 0.5ml | Preservative sensitivity | £9.30 | One use per vial | £9.30 to £18.60 |
| Eye Doctor Advanced 10ml | Oily tear film | £15.00 | Not stated | £15.00 on the 28 day rule |
The six we would buy
Hycosan Fresh
£9.99 on 16 Oct 2026 · 7.5ml · preservative free · £1.67 a month of use
The lightest drop in the Hycosan range and the cheapest of the six to actually use. The listing says 7.5ml and 225 drops, and that it can be used at least six months after first opening, which is what drags the monthly figure down to £1.67. It sat at number 10 in the Moisturising Eye Drops chart on 16 October 2026. Preservative free, so it suits people putting drops in more than four times a day, which is the point at which Guy's and St Thomas' advises moving off preserved drops.
The catch: it is the mildest formulation of the three Hycosan bottles here. If your eyes are still gritty by mid-afternoon on these, you are paying twice to arrive at the Extra anyway.
Check price on Amazon →Hyabak Preservative-Free Eye Drops
£11.99 on 16 Oct 2026 · 10ml · preservative free · £2.00 a month of use
The only bottle of the six that states both halves of the sum. Its listing says the bottle holds 300 drops and stays sterile for six months after opening, so you can work out the cost per drop and the cost per month without guessing anything. At 10ml it is the largest preservative-free bottle here, and it uses the ABAK one-way valve rather than a preservative to stay clean. Number six in the chart on 16 October 2026.
The catch: the six months and the 300 drops do not expire together. At four drops a day you empty it in about 75 days, so the six month figure only ever pays off for light users. Anyone dosing heavily is really buying drop count.
Check price on Amazon →Hycosan Extra
£12.98 on 16 Oct 2026 · 7.5ml · preservative free · £2.16 a month of use
This is the one Britain is actually buying. On 16 October 2026 it was number one in Moisturising Eye Drops and number 14 across the whole Health and Personal Care department, which is a far better signal than topping a narrow subcategory. The listing sells it for severe and persistent dry eyes, says 225 drops from a one-click dispenser, and states use for up to six months after first opening. Contact lens compatible.
The catch: 225 drops in a bottle you are allowed to keep for six months is a mismatch. Use it four times a day and it is empty in under two months, which puts the real cost nearer £6.50 a month than £2.16. The monthly figures in this guide assume the bottle lasts its stated life.
Check price on Amazon →Vizulize Dry Eyes Eye Drops 10ml
£2.92 on 16 Oct 2026 · 10ml · £2.92 a month on the 28 day rule
Under three pounds, and perfectly reasonable if your eyes only trouble you on the odd windy walk or long drive. It was number nine in the chart on 16 October 2026. For occasional use the 28 day limit never bites, because you will not have the bottle long enough to care.
The catch: the listing says nothing about how long it keeps once opened and does not describe itself as preservative free, so the standard 28 day instruction is what applies. Use it twice a day through a whole winter and you are buying five or six bottles, which costs more than one Hycosan Fresh.
Check price on Amazon →Clinitas Preservative Free Lubricant Eye Drops, 30 x 0.5ml
£9.30 on 16 Oct 2026 · 30 single-dose vials · £9.30 to £18.60 a month of use
Single-dose vials solve the problem bottles create. Nothing stays open, so nothing needs a preservative and nothing has to be binned on a date. That matters if preserved drops sting or if you are already using drops often enough that your optometrist has steered you away from them. Number eight in the chart on 16 October 2026, and the vials travel well because there is no bottle to leak.
The catch: the cost swings on how you use them. One vial a day gives you a month for £9.30, two a day gives you a fortnight for the same money, and the price per month lands somewhere between five and nine times the Hycosan Fresh figure either way. There is also more plastic.
Check price on Amazon →Eye Doctor Advanced Triple Action
£15.00 on 16 Oct 2026 · 10ml · lipid based · £15.00 a month on the 28 day rule
Most of this chart is water-holding hyaluronic acid, which helps when your eyes are not making enough tears. This one is built around a lipid instead, aimed at the other half of the problem, where tears are produced but evaporate too fast because the oily layer on top of them is poor. If warm compresses and lid hygiene are already part of your routine, this is the drop that matches. It was number 11 on 16 October 2026 and the listing states roughly 300 drops.
The catch: the dearest of the six and the listing states no in-use period, so on what it tells you it has to be treated as a 28 day bottle. That makes it £15.00 a month, nine times the Hycosan Fresh figure, for a bottle holding the same 300 drops as the £11.99 Hyabak. The maker may state longer somewhere else. The page you buy from does not.
Check price on Amazon →What the top 20 listings actually say
We opened all 20 product pages in Amazon UK's Moisturising Eye Drops chart on 16 October 2026 and counted what each listing states in its own copy, scoped to the title, the bullets, the specification tables and the product description. Four findings came out of it.
- Only 8 of the 20 state how long the product can be used after opening. The other 12 leave the number that decides the monthly cost off the page entirely.
- Thirteen of the 20 say they are preservative free. None of the 20 names a preservative, so the seven that are not described as preservative free do not tell you what is in them either.
- None of the 20 states a marketing authorisation number or calls itself a licensed medicine, and only two say in their own copy that they are medical devices. Those two are the Healthcare by Amazon drops and the Innoxa Blue Formula, which cites CE0051.
- Three of the 20 are sold for whitening or brightening the eye rather than for dryness: Ocufresh Bright and Moist at number four, Murine Bright and Moist at number five, and the Innoxa Blue Formula. Two of the top five sellers in a chart Amazon calls Moisturising Eye Drops are appearance products.
Sixteen of the 20 mention hyaluronic acid or sodium hyaluronate and only three mention a lipid, which is worth knowing if your dryness is the evaporative kind. The chart is overwhelmingly one chemistry.
Questions people ask
How long can I keep a bottle of eye drops once it is open?
Twenty eight days is the default. The Summary of Product Characteristics for Hypromellose Eye Drops BP tells you to discard the bottle 28 days after opening even if there is solution remaining, and Guy's and St Thomas' NHS Foundation Trust gives patients the same instruction for artificial tears. The exception is a preservative-free bottle with a one-way valve, where makers such as Hycosan and Hyabak state six months. If the listing says nothing, assume 28 days.
Are preservative-free eye drops worth the extra money?
If you use drops more than four times a day, yes. That is the threshold at which Guy's and St Thomas' advises preservative-free drops, because repeated exposure to the preservative can irritate the surface of the eye in its own right. Below that, the argument is mostly about cost, and a six month bottle usually wins there too.
Are eye drops a medicine or a medical device?
Both exist on the same shelf. Hypromellose Eye Drops BP is a licensed medicine with a marketing authorisation, PL 15872/0005. Many hyaluronic acid lubricating drops are CE or UKCA marked medical devices instead, which is a different regulatory route with different evidence behind it. None of the 20 Amazon listings we read on 16 October 2026 stated a PL number, and only two described themselves as medical devices.
Why is the cheapest bottle not the cheapest option?
Because you pay for the bottle and then throw away whatever you have not used by the deadline. A £2.92 bottle you must bin after 28 days costs £2.92 a month. A £12.98 bottle you can keep for six months costs £2.16 a month. The rank by price tag and the rank by cost of use are not the same list.
Will eye drops cure dry eye?
No. They are a lubricant, and they treat the symptom while you use them. Persistent dryness, pain, discharge or any change in vision is something to take to an optometrist or a GP rather than to a shopping list.
Sources
- Hypromellose Eye Drops BP, Summary of Product Characteristics, electronic medicines compendium, PL 15872/0005, text last revised 12 August 2020. Read 16 October 2026.
- Dry eye syndrome: treatment, Guy's and St Thomas' NHS Foundation Trust, last reviewed January 2026. Read 16 October 2026.
- Borderlines with medical devices and other products in Great Britain, MHRA, published 8 April 2024, updated 29 June 2026. Read 16 October 2026.
- Amazon UK Best Sellers in Moisturising Eye Drops, chart positions and the 20 product listings behind the audit. Read 16 October 2026.
Prices are the Amazon UK buy box read on 16 October 2026 and change without notice. Look Into is a member of the Amazon Associates programme and earns a commission on qualifying purchases made through the links above, at no extra cost to you. Nothing here is medical advice.