Eyeglasses | SmartBuyGlasses SG

Why Do I Need Thick Glasses Lenses?

Prescription lenses can vary drastically for each individual depending on their unique needs. The density of lenses may range from paper-thin to the 'coke bottle' effect. But why is this? 

 

If you have thick glasses, your prescription is likely stronger than most. But what is the purpose of thick glasses lenses? Prescription lenses bend the light through curved lenses as it enters your eye. Short-sighted wearers will have lenses that are thicker on the edge and thinner in the middle, while those who are long-sighted will have the opposite. 

 

Why are my glasses lenses so thick? 

To understand why you have thick glasses lenses, you need to be aware of the refractive index. This measures how much the path of light is bent (refracted) when it enters your lenses. Therefore, the stronger your prescription is, the thicker your lenses need to be to effectively bend the light. 

 

Another point to think about is your glasses' frame size and your pupillary distance. Lens thickness will increase as the frame size increases due to the edge of the lens being utilised to fit the frame. Therefore, the larger the frame, the thicker the lens can be with the same prescription and lens index. Your pupillary distance may also change where the thickness occurs to optimise your vision. 

 

How thick can glasses get?

How thick the glasses lens will be is determined by a few factors. The material of your lenses contribute to the thickness, as well as your prescription and personal choice. Thanks to new technology, high index lenses were introduced with thinner lenses than the traditional thick glasses. 

 

The high index lenses are made from a material that allows for better light refraction in a thin lens. Many people opt for high index lenses because they have a more sleek look. If you’re asking yourself, “Do I need high index lenses?” you can discover our thin lenses guide to get a better understanding of what they are and whether they are right for you.

 

Do prisms make glasses thicker?

Some eyewear users may experience double vision (diplopia) and need prism glasses to correct their eyesight. Prism glasses refract the light before entering your lenses rather than when it passes through. For this reason, it can be quite normal for one lens to be thicker than the other. However, experimenting with various frame styles can help hide the size difference if you feel it is too obvious or bothers you. 

 

Best glasses frames for thick lenses

Due to thick glasses being slightly heavier, some frames are better than others. For example, rimless glasses or thin designs won't give your thick lenses the support they need. So, what frames are best suited for thick lenses? 

 

If you have thick glasses lenses, you want to select frames that support the extra density. Oval or round glasses are best suited since they give your lenses 360° support. In terms of style, thicker or full rim glasses will work best to blend in with the thickness of your lenses. This style creates a seamless look that draws attention to the frames rather than the thick glasses. 


With a better understanding of thick glasses, you can now buy your prescription glasses with confidence. If you found this helpful and would like to know more, you can visit our article on glasses lens materials to become an expert on all types of lenses. Or, with a simple click, you can ask our opticians any other questions you may have!