Myopia Hyperopia Astigmatism Presbyopia

Myopia

Myopia is a vision problem in which vision is clear up close, but blurred from a distance. This occurs because the eye is longer than normal or because its optical system (cornea and lens) focuses light before it reaches the retina. Depending on how far away the eye is from the retina, the greater the degree of myopia.

Myopia usually begins in childhood and can increase each year, especially if the child spends a lot of time doing close-up tasks, such as reading or using screens, and spends little time outdoors.

Types:

● Axial: the eye is longer than normal.

● Curvature: the cornea or lens are more curved than normal.

● Index: This occurs due to changes in the lens, for example, in people with cataracts or diabetes.

Treatments:

● Minus (concave) lenses, either glasses or contact lenses.

● Myopia control in children: outdoor activities, reducing screen time or close-up work, special lenses, eye drops (such as atropine), or special contact lenses (orthokeratology).

● Refractive surgery: There are several options, and the best option is determined through an ophthalmologist consultation.

Hyperopia

Hyperopia is the opposite of myopia: you see better from a distance than from close up. This occurs when the eye is shorter than normal, or its optical system doesn't have enough power to focus properly, so light is focused behind the retina.

In young people, it's often not noticeable because the eye automatically compensates with visual effort (accommodation), but this can cause headaches, eye strain, and blurred vision, especially when reading or working up close.

Types:

● Axial: the eye is shorter.

● Curvature: the cornea is flatter than normal.

Treatments:

● Plus (convex) lenses, which help focus the image on the retina.

● In children, it's best diagnosed with drops that relax focusing.

● It can also be corrected with contact lenses or laser surgery to modify the curvature of the cornea.

In many cases, due to the way in which it is compensated almost automatically, the evaluation is usually carried out by cycloplegia (where through the application of a drug that reduces said effort, the correction found is more reliable.

Astigmatism

Astigmatism is a condition in which vision is blurred or distorted both at distance and near. This is because the cornea (or lens) is not perfectly round, but rather oval, like an American football, causing light to focus on several points instead of just one. Vision is reported as double or as if a shadow is seen around letters or lights.

Types:

● With the ruler: the main axis is vertical.

● Against the ruler: the main axis is horizontal.

● Oblique: at intermediate angles.

● Depending on how the focusing angles are combined, it can be:

● Myopic (focused before the retina),

● Hyperopic (behind the retina),

● Mixed (one part before and one part after).

Treatments:

● Cylindrical or toric lenses (in glasses or contact lenses).

● Refractive surgeries such as LASIK or PRK.

● In more complex cases, special implanted lenses are used.

Astigmatism can change with age. It is common in young children and usually decreases as children grow, but can increase after age 40.

Presbyopia.

Presbyopia (also known as tired eyes) is a natural physiological change in the eye that usually appears between the ages of 40 and 45. It consists of a progressive decrease in the ability to focus on close objects due to the loss of elasticity of the crystalline lens—the eye's natural lens—and the reduction in the strength of the ciliary muscle that accommodates it.

This process is part of the normal aging of the visual system and affects everyone, regardless of whether they previously had good vision or a refractive error such as myopia, hyperopia, or astigmatism. In the latter cases, one prescription is needed for distance vision and a different one for near vision.

Most common symptoms:

● Difficulty reading small text, especially in low-light conditions.

● Needing to move objects further away to see them clearly.

● Eye strain when performing close-up tasks, such as reading or writing.

● Headaches, especially at the end of the day or after prolonged periods of eye strain.

A patient may report that they used to read without difficulty, but now need to extend their arm to focus properly on their cell phone or a book, or remove their distance glasses. This complaint is often one of the first signs of presbyopia.

Presbyopia and eyeglass wear.

Optical correction is necessary because presbyopia cannot be prevented or reversed with medications or eye exercises. Corrective lenses, whether single-vision reading lenses, bifocal lenses, progressive lenses, or multifocal contact lenses, can compensate for the loss of accommodation and restore functional vision for near distances.

Timely use of these lenses significantly improves quality of life, makes daily tasks easier, and reduces symptoms associated with eye strain.

Consequences of not correcting it:

Although not wearing lenses will not worsen presbyopia or cause permanent eye damage, it can cause considerable discomfort such as continuous blurred vision, frequent headaches, eye irritation, and impaired work or academic performance, especially in activities that require prolonged close focus.