I have the same problem. Try here:
http://www.prescription-swimming-goggles.co.uk/acatalog/Adult_Prescription_Goggles.html
for an answer!

Contacts should be OK, but you wouldn't be able to use specs. So it'll either be contacts or get yourself a prescription mask, such as THIS (cheaper ones are on the market). Your local dive shop would be able to help.

Crumbs Ev, that's a pricey mask...

My daughter's cost about £40. Any decent dive shop can sort you out if you have your prescription, but avoid High Street opticians - they tried to fob us off with lenses that wedged inside the mask - hopeless, would be imposible to avoid fogging.

The goggles would be no good for snorkel/diving either - can't equalise air pressure in you ears with them and you'd be likely to get a squeeze if diving down for a closer look.

Hi there

I had the same dilema last year. I did wear hard lenses and was worried about loosing them when I snorkelled. I actually got a months worth of daily disposbile lenses. This way I could effectively "loose" one a day. I didn't loose any and they were so much more comfortable than hard lenses I now wear them all the time. The costs do vary. I had the Johnson & Johnson activue moist. They are about £32 for a months supply. I thought this was bargain for two weeks fantastic snorkelling. You can get cheaper ones. Speak to your opticians and you can trial them. I trial 3 lots before I made up my mind.

I know instructors who use contacts - no problem for diving except you may need to close your eyes to remove and replace your mask underwater. Even less of an issue snorkelling.

Like Trish can thoroughly recommend daily disposables for snorkelling!

Thank you for all your advice I will speak to my optician, I hadn't thought about daily disposables. I thought there was no hope for me. I have problems at waterparks too, being worried about losing lenses etc can be a really spoiler!

The good thing about disposables is that if you get water in your eye and you feel the hygiene is compromised you can just change the lens for another! Just a hint though, if you are on a boat or beach make sure you are protected from the wind when putting them in - have lost a couple this way, but fortunately take a few with me each time!