What does 1.5 index lenses mean?

What does 1.5 index lenses mean?

Individuals with a weak prescription who want to save money on lenses may opt for a 1.5 standard index lens. This type of lens is suitable for prescriptions with an SPH correction of +/- 2.25 and less, or a CYL correction of +/- 1.50 and less.

Is the a big difference between 1.57 and 1.61 index lenses?

The main difference between 1.57 and 1.61 index lenses is the thickness of the lens material. ... If the lens power is approximately -4.00, it may be more suited to opt for 1.61 index lenses. The thickness is around 3mm to 4mm.

What is a high index prescription?

A high index lens is a lens that has a higher "index" of refraction. This means it has a greater ability to bend light rays to provide clear vision for people with stronger prescription glasses. ... High index lenses are manufactured to be thinner at the edges of the lens and lighter in weight overall.

Is 1.60 A high index?

High index lenses come in a variety of indices ranging from 1.53 to 1.74, with “true” high index starting at an index of at least 1.60. ... In fact, high index lenses of 1.60 or higher typically result in a 25% – 50% reduction in overall lens weight compared to conventional lenses.Feb 25, 2021

Is 1.5 A high index?

A high-index lens may be recommended if your optical prescription is above 2.00 diopters. High-index lenses have a refractive index above 1.50— ranging from 1.53 to 1.74. The image below compares the lens thickness of a regular plastic lens (1.50) to the most commonly prescribed high-index lenses.Nov 25, 2020

What is 1.5 index single vision lenses?

1.5 Index — Standard Lens These single-vision lenses are the most basic option we offer, and come free with all EyeBuyDirect frames. This index is most suitable for prescriptions with an SPH correction of +/-2.25 and below, or a CYL correction of +/-1.50 and below.Sep 27, 2020

What index should my glasses be?

What does lens index mean? As the prescription strength increases, lenses get thicker and heavier. Higher-index material provides thinner and lighter lenses, which makes them a good option for those who have a strong prescription. Typically, the index numbers range from 1.50 to 1.74.

What is the difference between 1.59 and 1.6 index lenses?

The 1.59 is probably polycarbonate which will be lighter and impact resistant, but does have a little bit of distortion. Versus the 1.6 lens will be more optically clear, but will be heavier and not impact resistant (if that is important for your lifestyle).

What is a 1.5 index?

1.5 Index Lens is standard A lenses index defines how thick the lens is, the higher the index the thinner the lens. ... As your prescription becomes stronger the lens becomes thicker, therefore stronger prescriptions should be using higher index lenses to reduce their physical thickness.