eyeglasses too thick

[aluminex]

If someone would be so kind as to explain or enlighten me on the subject I would be most appreciative.

I recently purchased a new set of glasses. After picking them up I was surprised to see the thickness of my lenses had increased somewhat dramatic. The prescription is relatively the same as before but the thickness of the lenses has more than doubled. I have been told the reasoning is because the eye size of my new frames is larger thus requires more thickness.

Here in my prescription and frame info:

OD
Sphere: +5.25
Cylinder: -4.25
Axis: 173

OS:
Sphere: +5.50
Cylinder: -4.75
Axis: 004

Frame: Plastic
Lens Width: 57mm
Lens Height: 29mm


Here is my lens thickness:
New lens: 7-8mm thick
Old lens: 3-4mm

Pictures:
http://www.shudew.org/size.jpg

 

[Threak]

A few factors contribute to lens thickness. First of all, your prescription is very strong. Also, as you mentioned, the size of your frames is a factor. Lenses have a cross section that looks kind of like this: )|, thinner in the middle and thicker on the edges the further out they extend. Lastly, the material of the lens affects how thick it must be. Plastic is the cheapest, but usually upgrades to higher index materials are available (referring to their refractive index; how much they bend light). These upgrades can start at ~$20, and up to $80+ for the thinner and lighter materials.

 

[eyegizmo]

Since you prescription is pretty high the thickness of the lenses will be prominent. Try to select a smaller frame or a plastic frame to avoid the thickness of the lenses. The other option will be to upgrade the lenses to 1.60 or 1.67 index lenses these lenses will be thinner.

 

[vaalbara]

i wish my prescription was still as low as yours

 

[Crass]

Look into high-index aspheric lenses, my personal recommendation is Zeiss. Both factors, high-index and aspheric, serve to produce a much thinner lens. If you are willing to go balls to the wall, Zeiss offers 1.74 polycarbonate lenses and even 1.8+ glass lenses. They also have the best lens coatings available. Lens shape is determined by whether you are near or farsighted. Nearsighted, lenses are thinner in the middle and thicker on the outside and vice-versa for farsighted. Check out http://www.allaboutvision.com/lenses/highindx.htm I recommend that you don't order your glasses online as the range of quality from lens cutter to lens cutter can vary. Your optometrist should have an idea about how the frame will affect your lens thickness.

 

[commodorewheeler]

Originally Posted by aluminex

If someone would be so kind as to explain or enlighten me on the subject I would be most appreciative.

I recently purchased a new set of glasses. After picking them up I was surprised to see the thickness of my lenses had increased somewhat dramatic. The prescription is relatively the same as before but the thickness of the lenses has more than doubled. I have been told the reasoning is because the eye size of my new frames is larger thus requires more thickness.

Here in my prescription and frame info:

OD
Sphere: +5.25
Cylinder: -4.25
Axis: 173

OS:
Sphere: +5.50
Cylinder: -4.75
Axis: 004

Frame: Plastic
Lens Width: 57mm
Lens Height: 29mm


Here is my lens thickness:
New lens: 7-8mm thick
Old lens: 3-4mm

Pictures:
http://www.shudew.org/size.jpg

Did your lens material change from your old glasses to your new ones?

With your type of prescription (a farsighted or "plus" prescription), your glasses lenses are actually going to be thickest in the middle instead of on the edges, so increasing the eye size shouldn't make the lenses thicker. Assuming that you didn't mistype your prescription above, only a lens material change (such as going from polycarbonate on your old lenses to plastic on your new ones) would account for such a dramatic difference in thickness if your prescription is about the same as before.