What’s In A Glasses Prescription?
What’s In A Glasses Prescription?
When it comes to eyeglass prescriptions, one size certainly does not fit all. The diversity in prescriptions stems from the unique ways in which each person’s eyes perceive and process visual information. Understanding why prescriptions differ involves delving into the various visual issues and the tailored solutions designed to address them.
During your eye health exam at Envision, we’ll focus on the reason for your eyeglass prescriptions and help you understand the purpose for their use. Oftentimes, like the shoes we wear for different activities, we find patients benefit from different prescriptions based on their different daily demands with their eyes. All of this comes down to refractive errors, which occur when the eye’s ability to focus light on the retina is compromised. The three most common types are:
- Nearsightedness (Myopia): This condition causes distant objects to appear blurry while close-up vision remains clear. Myopia happens when the eye is too long or the cornea is too curved, leading light to focus in front of the retina. Eyeglasses for myopia use concave lenses (thinner at the center and thicker at the edges) to help focus light directly on the retina.
- Farsightedness (Hyperopia): Here, nearby objects are blurry while distant vision remains sharp. Hyperopia occurs when the eye is too short or the cornea is too flat, causing light to focus behind the retina. Convex lenses (thicker in the center and thinner at the edges) are used to bring light forward onto the retina.
- Astigmatism: This condition results from an irregularly shaped cornea or lens, causing distorted or blurred vision at all distances. Astigmatism is corrected with cylindrical lenses that compensate for the eye’s uneven curvature, allowing for more accurate light focus.
As people age, they often experience Presbyopia, an age-related condition where the lens loses its flexibility, making it difficult to focus on close objects. Presbyopia typically requires multifocal lenses, such as bifocals or progressive lenses, which combine different optical strengths in one lens to aid in both near and distant vision.
Lifestyle factors also influence prescription needs. For example, someone who spends long hours in front of a computer may experience digital eye strain, and their eyes need a specific prescription, such as an Antifatigue Lens, to help focus for long periods at a certain distance, like sewing, reading or computer work.
Furthermore, prescriptions are individualized based on the specific measurements of each eye, including the curvature of the cornea and the distance between the pupils. We conduct thorough eye exams to determine these measurements and create a precise prescription tailored to our patients visual requirements.
The variation in eyeglass prescriptions reflects the complexity of human vision and the need for personalized correction. Each prescription is a carefully crafted solution designed to address specific visual challenges, ensuring that every individual can achieve the clearest and most comfortable vision possible.
If you notice eye fatigue, headaches or eye strain during specific activities in your day-to-day life, let our doctors know at your next comprehensive exam! Give us a call at 828-254-6757, or schedule your next yearly eye health exam online.
