What is the difference between orthokeratology lenses and contact lenses

What is the difference between orthokeratology lenses and contact lenses

Orthokeratology lenses, which are commonly referred to as OK lenses. It is designed with a special inverse geometry, and its inner surface is made up of multiple arcs. The geometry of the cornea is changed by physical pressure and worn on the front of the cornea while sleeping, which gradually flattens the curvature of the cornea and shortens the eye axis, thus effectively preventing the progression of myopia. So, what is the difference between orthokeratology lenses and regular contact lenses? Unlike regular contact lenses, orthokeratology lenses are worn at night while sleeping and can restore normal vision the next day, and can restore normal vision without wearing glasses during the day. At the same time, more advanced than ordinary contact lenses, orthokeratology lenses can effectively prevent and treat the development of myopia, and this advantage over ordinary contact lenses has been certified at home and abroad. Clinical studies have shown that wearing regular glasses increases myopia by an average of 67 degrees per year, while wearing orthokeratology lenses only increases by 8 degrees per year. The difference between orthokeratology lenses and general contact lenses Orthokeratology lenses are currently the most effective method to correct and control myopia in adolescents, compared with ordinary contact lenses, the differences between orthokeratology lenses and general contact lenses are mainly as follows: 1. The oxygen permeability value is different: the oxygen permeability value of orthokeratology lens can generally reach 120, which exceeds the oxygen permeability of 90 required for night wear contact lenses stipulated by the state. In addition, ordinary contact lens lenses are often larger than the black eyeball, affecting the breathing of the eyes and the circulation of tears. 2. Different wearing time: Orthokeratology lenses can gently reshape the corneal epidermis, only need to be worn at night, and can improve vision by about 1.0 during the day. Ordinary contact lenses are worn during the day, and they are prone to keratitis and dry eyes due to the influence of the environment and wind and sand, which can lead to corneal ulcers in severe cases. 3. Different safety for the cornea: when wearing orthokeratology lenses, the lens is required to be filled with eye moisturizer, and then put on, there is a layer of liquid between the eye and the lens, which is easy to alternate tears, and will not form direct wear and tear on the cornea, so as to maintain safety. When wearing ordinary contact lenses, they are directly attached to the cornea, which is easy to rub the cornea, hinder the alternation of tears, and is easily affected by the environment and wind and sand, which can easily form keratitis and dry eyes, and in severe cases, it will lead to corneal ulcers. 4. Different correction range: Orthokeratology lenses have a wide correction range, myopia patients within 500 degrees can quickly achieve a visual acuity of more than 5.0 in 1-2 weeks, and specially customized orthokeratology lenses can also correct astigmatism at a high level. However, the scope of vision correction of ordinary contact lenses is limited, and the correction effect of astigmatism is poor. 5. Different service life: Orthokeratology lenses have a long service life, using special technology, the lenses are easier to preserve, clean and breathable, and can generally be used for about 2 years. However, ordinary contact lenses have a short service life, generally no more than 1 year, and need to be replaced regularly in a short period of time, which is costly. Ordinary contact lenses should be cleaned and maintained, and improper wearing methods can cause inflammation of the cornea and conjunctiva. 6. Whether it can prevent the development of myopia: Orthokeratology lenses can not only correct myopia, but also effectively prevent and control the growth of myopia. However, general contact lenses can only correct myopia, but cannot control the growth of myopia. According to the expert of available glasses, orthokeratology lenses belong to three types of medical devices and need to be fitted in regular hospitals. Many parents of children with increasing myopia should first take their children for a comprehensive examination to see if they are suitable, and after passing the examination, the doctor will tailor the lenses for you according to your examination results, and the patient needs to return to the hospital regularly for relevant re-examinations after wearing