Diopters for farsightedness typically range from +0.25 to +4.00. The specific diopter strength needed for farsightedness depends on the individual's degree of farsightedness. An eye examination by an optometrist or ophthalmologist is necessary to determine the exact diopter strength required for correcting farsightedness. **

The term "diopters" refers to the measurement of the refractive power of a lens or the eye's ability to focus. Whether diopters are considered high or not depends on the context. In the case of eyeglasses or contact lenses, a higher number of diopters indicates a stronger prescription, which may be considered high for some individuals. However, in the context of eye surgery such as LASIK, the amount of diopters being corrected may be considered high if it is a significant amount of refractive error being addressed. Ultimately, whether diopters are considered high is subjective and depends on individual circumstances. **

Visual diopters are a unit of measurement used to quantify the refractive power of a lens. They indicate how much a lens can converge or diverge light rays. Positive diopters indicate converging lenses that correct for farsightedness, while negative diopters indicate diverging lenses that correct for nearsightedness. Visual diopters are commonly used in optometry to prescribe corrective lenses for individuals with refractive errors. **

Yes, diopters are added together when calculating the total power of a lens system. When multiple lenses are combined, their individual powers are algebraically added to determine the overall power of the system. This is a fundamental principle in optics and is used in the design and prescription of corrective lenses for vision correction. **

A 13-year-old with 12 diopters would have a total of 24 diopters. This is because the diopter measurement is additive, so if the child already has 12 diopters and then adds another 12 diopters, the total would be 24 diopters. **

The calorie expenditure for road cycling and mountain biking can vary based on factors such as intensity, terrain, and duration. Generally, road cycling on flat terrain at a moderate pace can burn around 400-600 calories per hour, while mountain biking on varied terrain with hills and obstacles can burn around 500-800 calories per hour. The higher calorie expenditure in mountain biking is due to the increased effort required to navigate the challenging terrain and obstacles. Overall, mountain biking tends to result in a higher calorie expenditure compared to road cycling. **

Swimming goggles with diopters are designed for individuals who require vision correction while swimming. These goggles have built-in lenses with specific diopter strengths to help swimmers see clearly underwater. They are available in a variety of diopter strengths to accommodate different levels of vision impairment. Swimmers can choose the appropriate diopter strength based on their prescription to enjoy a clear and comfortable swimming experience. **

It is not specified in the question how many diopters have worsened. If you have a specific case or situation in mind, please provide more details so that I can give you a more accurate answer. **