Anyone know about glasses prescriptions?

[AriettyHomily]

I am long time contact lens wearer, I only wear my glasses in emergencies (like today when my lenses are stuck somewhere with the royal mail...).

My glasses prescription is -3 and -2.75, my contact lenses are -2.5 and have been for years. I cannot get on with the bloody glasses. Why is the prescription different? do I need to get the glasses at 2.5 as well?

Contact lenses are generally slightly different as they sit on your eye, whereas with glasses there is a gap between the eye and the lens.

Same as previous poster, glasses and contact lens tend to have a slightly different prescription. When was the last time you had an eye test? Maybe your prescription has changed but only noticeable with the glasses.

The first answer is correct. It's different because contact lenses are on your eye where as glasses are further away

I had the same problem where lenses were fine, couldn't wear glasses. Turns out they were centred incorrectly so the lens was the wrong thickness. Might be worth checking. But as others said, lens and glasses prescription won't be the same.